diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_codex_audit.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_codex_audit.rs
index 6f8557a32..b3d60bc64 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_codex_audit.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_codex_audit.rs
@@ -550,6 +550,7 @@ fn extract_mcp_arguments(root: &Path, tool: &str, arguments: &Value) -> Value {
         "agc_generate_image" => {
             copy_string(object, "kind", &mut out);
             copy_string(object, "sliceMode", &mut out);
+            copy_string(object, "screenColor", &mut out);
             copy_string(object, "aspectRatio", &mut out);
             copy_string(object, "imageSize", &mut out);
             copy_string(object, "assetName", &mut out);
diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_runtime/mod.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_runtime/mod.rs
index 706015112..91bc4ad1c 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_runtime/mod.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_runtime/mod.rs
@@ -3390,6 +3390,7 @@ async fn generate_direct_taonier_art_asset_at(
         slice_mode: (asset_kind == "art-spritesheet").then(|| "connected-components".to_string()),
         grid_x: None,
         grid_y: None,
+        screen_color: None,
     };
     let runtime_context =
         direct_taonier_art_generation_runtime_context(root, output_path, asset_kind)?;
diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs
index 9984ff4d6..164bd1543 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs
@@ -2230,6 +2230,42 @@ fn validate_generate_image_slice_declaration(
     Ok(())
 }
 
+/// 抠图纯色背景只服务 character 与 art-spritesheet 链路；格式校验收口为
+/// `auto` 或 `#RRGGBB`（服务端另有支持色板，客户端不复制），`auto`/空串归一为
+/// None（服务端自动决策），hex 统一大写后透传。其它 kind 携带该字段直接拒绝，
+/// 避免服务端静默忽略造成“已生效”的误解。
+fn normalize_generate_image_screen_color(
+    arguments: &Value,
+    kind: &str,
+) -> Result<Option<String>, String> {
+    let Some(value) = arguments.get("screenColor") else {
+        return Ok(None);
+    };
+    if value.is_null() {
+        return Ok(None);
+    }
+    if !matches!(kind, "character" | "art-spritesheet") {
+        return Err(format!(
+            "工具参数 screenColor 仅对 kind=character 和 kind=art-spritesheet 生效，当前 kind={kind}"
+        ));
+    }
+    let raw = value
+        .as_str()
+        .ok_or_else(|| "工具参数 screenColor 必须是 auto 或 #RRGGBB".to_string())?
+        .trim();
+    if raw.is_empty() || raw.eq_ignore_ascii_case("auto") {
+        return Ok(None);
+    }
+    let normalized = raw.to_ascii_uppercase();
+    let valid = normalized.len() == 7
+        && normalized.starts_with('#')
+        && normalized[1..].chars().all(|c| c.is_ascii_hexdigit());
+    if !valid {
+        return Err("工具参数 screenColor 必须是 auto 或 #RRGGBB".to_string());
+    }
+    Ok(Some(normalized))
+}
+
 async fn bridge_generate_image(state: &DirectToolBridgeState, arguments: &Value) -> Value {
     let result = async {
         bridge_reject_unknown_fields(
@@ -2244,6 +2280,8 @@ async fn bridge_generate_image(state: &DirectToolBridgeState, arguments: &Value)
                 "sliceMode",
                 "gridX",
                 "gridY",
+                "sliceCount",
+                "screenColor",
             ],
         )?;
         enforce_project_permission_policy(&state.root, "canvas.asset_generate")?;
@@ -2323,13 +2361,25 @@ async fn bridge_generate_image(state: &DirectToolBridgeState, arguments: &Value)
         {
             return Err("工具参数 gridX/gridY 必须在 1 到 32 之间".to_string());
         }
+        let slice_count = arguments
+            .get("sliceCount")
+            .filter(|value| !value.is_null())
+            .map(|value| {
+                value
+                    .as_u64()
+                    .filter(|count| (1..=256).contains(count))
+                    .map(|count| count as usize)
+                    .ok_or_else(|| "工具参数 sliceCount 必须是 1 到 256 的整数".to_string())
+            })
+            .transpose()?;
         validate_generate_image_slice_declaration(
             kind.as_str(),
             slice_mode.as_deref(),
             grid_x,
             grid_y,
-            None,
+            slice_count,
         )?;
+        let screen_color = normalize_generate_image_screen_color(arguments, kind.as_str())?;
         let options = PlatformArtAssetGenerationOptions {
             output_path,
             aspect_ratio,
@@ -2337,10 +2387,11 @@ async fn bridge_generate_image(state: &DirectToolBridgeState, arguments: &Value)
             asset_kind: kind.clone(),
             asset_label: asset_name.clone(),
             replace_existing: false,
-            slice_count: None,
+            slice_count,
             slice_mode,
             grid_x,
             grid_y,
+            screen_color,
         };
         let _generation_guard = state.image_generation_gate.lock().await;
         let generated = with_direct_editor_api_credentials(
@@ -2867,6 +2918,61 @@ mod tests {
         assert!(validate_generate_image_slice_declaration("image", None, None, None, None).is_ok());
     }
 
+    #[test]
+    fn generate_image_screen_color_is_normalized_and_kind_gated() {
+        // 省略与显式 null 等价，且不触发 kind 门禁。
+        assert_eq!(
+            normalize_generate_image_screen_color(&json!({}), "image").expect("omitted"),
+            None
+        );
+        assert_eq!(
+            normalize_generate_image_screen_color(&json!({"screenColor": null}), "image")
+                .expect("null"),
+            None
+        );
+        // auto 家族归一为 None（服务端自动决策），大小写与空白不敏感。
+        for raw in ["auto", "AUTO", " auto ", ""] {
+            assert_eq!(
+                normalize_generate_image_screen_color(&json!({"screenColor": raw}), "character")
+                    .expect("auto variants"),
+                None,
+                "{raw}"
+            );
+        }
+        // hex 统一大写透传；色板白名单由服务端权威校验，客户端只守格式。
+        assert_eq!(
+            normalize_generate_image_screen_color(&json!({"screenColor": "#cfefff"}), "character")
+                .expect("lowercase hex"),
+            Some("#CFEFFF".to_string())
+        );
+        assert_eq!(
+            normalize_generate_image_screen_color(
+                &json!({"screenColor": " #A0BBA0 "}),
+                "art-spritesheet"
+            )
+            .expect("padded hex"),
+            Some("#A0BBA0".to_string())
+        );
+        // 非 auto/非 hex、非字符串一律拒绝。
+        for bad in [json!("green"), json!("#GGGGGG"), json!("#FFF"), json!(12)] {
+            assert!(
+                normalize_generate_image_screen_color(&json!({"screenColor": bad}), "character")
+                    .is_err(),
+                "{bad}"
+            );
+        }
+        // 其它 kind 携带该字段直接拒绝，即使取值合法。
+        let gated =
+            normalize_generate_image_screen_color(&json!({"screenColor": "#CFEFFF"}), "image")
+                .expect_err("screenColor must stay scoped to character/art-spritesheet");
+        assert!(gated.contains("kind=character"), "{gated}");
+        assert!(normalize_generate_image_screen_color(
+            &json!({"screenColor": "auto"}),
+            "ui-prototype"
+        )
+        .is_err());
+    }
+
     #[test]
     fn remove_background_identity_preserves_default_and_distinguishes_options() {
         let legacy = "asset-1\0透明图";
diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs
index e9d9415df..718a30ddd 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs
@@ -233,7 +233,7 @@ fn direct_tools_mcp_specs_for(controlled_web_search: bool, _cocos_editor_availab
         }),
         json!({
                 "name": "agc_generate_image",
-                "description": "按原网站图片画布能力生成一张新图片：普通插画、角色立绘、统一视觉规范图、游戏 UI 设计图或透明游戏素材图集都可使用。仅在用户明确要求生成新图时调用；游戏美术包是另一个专用工具，不是本工具的限制。客户端负责登录态授权、计费、幂等账本、下载校验、manifest/revision 登记和本地预览，不需要用户提供 API Key、Token、URL 或 .env。",
+                "description": "按原网站图片画布能力生成一张新图片：普通插画、角色立绘、统一视觉规范图、游戏 UI 设计图或透明游戏素材图集都可使用。仅在用户明确要求生成新图时调用。",
                 "inputSchema": {
                     "type": "object",
                     "properties": {
@@ -286,6 +286,16 @@ fn direct_tools_mcp_specs_for(controlled_web_search: bool, _cocos_editor_availab
                             "minimum": 1,
                             "maximum": 32,
                             "description": "grid 模式纵向网格数量，只能与 sliceMode=grid 同时提供"
+                        },
+                        "sliceCount": {
+                            "type": "integer",
+                            "minimum": 1,
+                            "maximum": 256,
+                            "description": "只与 kind=art-spritesheet 且 sliceMode=connected-components 同时提供，用于约束目标素材张数；省略时按图像内容自动识别"
+                        },
+                        "screenColor": {
+                            "type": "string",
+                            "description": "抠图纯色背景，仅 kind=character（角色形象）和 kind=art-spritesheet（图标素材）生效，其它 kind 携带会被拒绝。生成时把主体置于该纯色背景上，回图后据此抠除背景。取值只能是 auto 或下列色板 hex 之一，传值只填 hex 本身、不要附带色名：#CFEFFF（浅雾蓝）、#B0C2E0（浅钢蓝）、#FFD6C2（暖浅桃色）、#E6D8FF（淡薰衣草紫）、#F4D8E8（浅粉灰）、#7FB3FF（中度天蓝）、#FFF2A8（浅柠黄）、#CFFFE1（淡薄荷绿）、#D8DEE8（浅中性灰）、#D8D2E8（淡灰紫）、#A8F7F0（高对比浅青）、#A0BBA0（灰竹绿）；auto 时由服务端自动选色。手动指定时不能与角色或素材本体的颜色接近"
                         }
                     },
                     "required": ["prompt"],
@@ -1131,6 +1141,8 @@ async fn call_agc_generate_image(arguments: &Value) -> Value {
             "sliceMode",
             "gridX",
             "gridY",
+            "sliceCount",
+            "screenColor",
         ],
     ) {
         return mcp_tool_result(error, Vec::new(), true);
@@ -1159,6 +1171,7 @@ async fn call_agc_generate_image(arguments: &Value) -> Value {
         ("assetName", DIRECT_TOOLS_MCP_MAX_RESOURCE_NAME_CHARS),
         ("outputPath", 512),
         ("sliceMode", 32),
+        ("screenColor", 16),
     ] {
         if arguments.get(field).is_some() {
             if let Err(error) = bounded_tool_string(arguments, field, max_chars) {
@@ -2391,11 +2404,27 @@ mod tests {
         assert_eq!(image_tool["inputSchema"]["required"], json!(["prompt"]));
         assert!(image_tool["description"]
             .as_str()
-            .is_some_and(|description| description.contains("不是本工具的限制")));
+            .is_some_and(|description| description.contains("仅在用户明确要求生成新图时调用")));
         assert_eq!(
             image_tool["inputSchema"]["properties"]["sliceMode"]["enum"],
             json!(["connected-components", "grid"])
         );
+        assert_eq!(
+            image_tool["inputSchema"]["properties"]["sliceCount"]["minimum"],
+            json!(1)
+        );
+        assert_eq!(
+            image_tool["inputSchema"]["properties"]["sliceCount"]["maximum"],
+            json!(256)
+        );
+        assert!(
+            image_tool["inputSchema"]["properties"]["screenColor"]["description"]
+                .as_str()
+                .is_some_and(|description| description.contains("抠图纯色背景")
+                    && description.contains("kind=character")
+                    && description.contains("不要附带色名")),
+            "screenColor description must carry the matting-background semantics"
+        );
         assert!(
             image_tool["inputSchema"]["properties"]["sliceMode"]
                 .get("default")
diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/generation/canvas_generation.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/generation/canvas_generation.rs
index a3b5be2a0..39857aff7 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/generation/canvas_generation.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/generation/canvas_generation.rs
@@ -420,6 +420,9 @@ pub(crate) struct PlatformArtAssetGenerationOptions {
     pub(crate) slice_mode: Option<String>,
     pub(crate) grid_x: Option<u32>,
     pub(crate) grid_y: Option<u32>,
+    /// 抠图纯色背景（auto/省略已归一为 None；Some 时是规范化后的大写 #RRGGBB）。
+    /// 仅 character 与 art-spritesheet 链路透传给服务端。
+    pub(crate) screen_color: Option<String>,
 }
 
 impl Default for PlatformArtAssetGenerationOptions {
@@ -435,6 +438,7 @@ impl Default for PlatformArtAssetGenerationOptions {
             slice_mode: None,
             grid_x: None,
             grid_y: None,
+            screen_color: None,
         }
     }
 }
@@ -2206,6 +2210,8 @@ pub(crate) async fn generate_platform_art_asset_with_required_slices_at(
 ///
 /// 升级前遗留账本仍由旧材料函数定位；新请求把显式切分模式纳入身份，避免同一图集
 /// 请求在网格与连通域之间误复用。`slice_count` 继续保持历史兼容语义，不进身份。
+/// `screen_color` 是付费语义不同的输入，进入身份；None 时跳过序列化，未使用该字段的
+/// 请求身份与升级前逐字节一致。
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
 struct StandalonePlatformArtGenerationFingerprintMaterial<'a> {
@@ -2220,6 +2226,8 @@ struct StandalonePlatformArtGenerationFingerprintMaterial<'a> {
     slice_mode: Option<&'a str>,
     grid_x: Option<u32>,
     grid_y: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    screen_color: Option<&'a str>,
 }
 
 /// 把输出路径收口成稳定的旧槽材料：空路径与未指定路径都落到 `(automatic-output)`，
@@ -2259,6 +2267,7 @@ fn standalone_platform_art_generation_runtime_context(
         slice_mode: options.slice_mode.as_deref(),
         grid_x: options.grid_x,
         grid_y: options.grid_y,
+        screen_color: options.screen_color.as_deref(),
     })
     .map_err(|error| format!("序列化 standalone 图片生成动作身份失败：{error}"))?;
     let action_fingerprint = format!("{:x}", Sha256::digest(&identity_bytes));
@@ -2833,7 +2842,7 @@ pub(in crate::agent) async fn request_platform_art_asset_with_runtime_options_at
                     "sliceMode": options.slice_mode,
                     "gridX": options.grid_x,
                     "gridY": options.grid_y,
-                    "screenColor": "auto",
+                    "screenColor": options.screen_color.as_deref().unwrap_or("auto"),
                     "aspectRatio": options.aspect_ratio,
                     "imageSize": options.image_size,
                     "assetLabel": options.asset_label,
@@ -2881,6 +2890,14 @@ pub(in crate::agent) async fn request_platform_art_asset_with_runtime_options_at
                 if options.asset_kind == "image" {
                     object.remove("kind");
                 }
+                if options.asset_kind == "character" {
+                    if let Some(screen_color) = options.screen_color.as_deref() {
+                        object.insert(
+                            "screenColor".to_string(),
+                            serde_json::Value::String(screen_color.to_string()),
+                        );
+                    }
+                }
             }
             request_body
         } else {
@@ -8429,6 +8446,7 @@ mod canvas_generation_tests {
             slice_mode: None,
             grid_x: None,
             grid_y: None,
+            screen_color: None,
         };
         let ordinary =
             standalone_platform_art_generation_runtime_context("完整生成提示词", &options, false)
@@ -8495,6 +8513,9 @@ mod canvas_generation_tests {
         let mut changed = options.clone();
         changed.replace_existing = false;
         changed_options.push(changed);
+        let mut changed = options.clone();
+        changed.screen_color = Some("#CFEFFF".to_string());
+        changed_options.push(changed);
         for changed in changed_options {
             let context = standalone_platform_art_generation_runtime_context(
                 "完整生成提示词",
@@ -10473,6 +10494,7 @@ mod canvas_generation_tests {
             slice_mode: None,
             grid_x: None,
             grid_y: None,
+            screen_color: None,
         };
         let prompt = "生成同一套整包美术";
         let generation_prompt = build_platform_art_asset_prompt(prompt, &[], &options);
@@ -11377,6 +11399,7 @@ mod canvas_generation_tests {
             slice_mode: None,
             grid_x: None,
             grid_y: None,
+            screen_color: None,
         };
         let prompt = "保持同一个生成提示词";
         let generation_prompt = build_platform_art_asset_prompt(prompt, &[], &options);
@@ -11841,6 +11864,7 @@ mod canvas_generation_tests {
             slice_mode: None,
             grid_x: None,
             grid_y: None,
+            screen_color: None,
         };
         let prompt = "恢复已受理视觉规范图";
         let generation_prompt = build_platform_art_asset_prompt(prompt, &[], &options);
@@ -12450,6 +12474,7 @@ mod canvas_generation_tests {
             slice_mode: Some("connected-components".to_string()),
             grid_x: None,
             grid_y: None,
+            screen_color: None,
         }
     }
 
diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/runtime_tools/media.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/runtime_tools/media.rs
index 5ba2980c2..5c1e7ffda 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/runtime_tools/media.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/runtime_tools/media.rs
@@ -577,6 +577,7 @@ pub(in crate::agent) async fn observe_agent_runtime_platform_art_asset_generatio
         slice_mode: (!slice_mode.trim().is_empty()).then_some(slice_mode.clone()),
         grid_x,
         grid_y,
+        screen_color: None,
     };
     if let Some(pending) = pending_action {
         match recover_persisted_visual_generation_options(
@@ -628,6 +629,7 @@ pub(in crate::agent) async fn observe_agent_runtime_platform_art_asset_generatio
                 .or_else(|| (!slice_mode.trim().is_empty()).then_some(slice_mode)),
             grid_x,
             grid_y,
+            screen_color: requested_options.screen_color,
         }
     };
     options.replace_existing = replace_existing;
diff --git a/apps/ai-game-creator-shell/src-tauri/src/commands.rs b/apps/ai-game-creator-shell/src-tauri/src/commands.rs
index a2e86d06e..426efa9b8 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/commands.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/commands.rs
@@ -4914,6 +4914,7 @@ pub(crate) fn prepare_local_project_asset_generation(
                 .then(|| "connected-components".to_string()),
             grid_x: None,
             grid_y: None,
+            screen_color: None,
         },
     })
 }
diff --git a/apps/ai-game-creator-shell/src-tauri/src/tests/project.rs b/apps/ai-game-creator-shell/src-tauri/src/tests/project.rs
index 0552c041e..145aabd36 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/tests/project.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/tests/project.rs
@@ -1094,6 +1094,7 @@ async fn canonical_art_spec_and_ui_requests_use_the_shared_reference_chain() {
             slice_mode: None,
             grid_x: None,
             grid_y: None,
+            screen_color: None,
         },
     )
     .await;
@@ -5574,6 +5575,7 @@ fn ui_prototype_generation_uses_dedicated_prompt_and_art_spec() {
         slice_mode: None,
         grid_x: None,
         grid_y: None,
+        screen_color: None,
     };
     let prompt = build_platform_art_asset_prompt(
         "原创网格贪吃蛇：分数与状态 HUD、四类不同分值食物、开始、方向键/WASD、触控方向键、失败与重开",