diff --git a/crates/oxide_regalloc/src/color.rs b/crates/oxide_regalloc/src/color.rs
index 65028ffd..275a0e13 100644
--- a/crates/oxide_regalloc/src/color.rs
+++ b/crates/oxide_regalloc/src/color.rs
@@ -202,161 +202,3 @@ fn assemble(
         arg_window_base,
     })
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use oxide_bytecode::opcode::OpCode;
-    use oxide_ir::inst::Inst;
-    use oxide_ir::operand::Operand;
-    use oxide_ir::IRFunction;
-
-    fn empty_function() -> IRFunction {
-        IRFunction::new()
-    }
-
-    fn color_of(
-        insts: Vec<Inst>, param_layout: oxide_ir::ParamLayout, nested: Vec<IRFunction>,
-    ) -> Result<AllocMap, String> {
-        let mut f = empty_function();
-        f.insts = insts;
-        f.param_layout = param_layout;
-        f.nested = nested;
-        let cfg = oxide_cfg::build_cfg(&f);
-        let live = oxide_liveness::liveness(&f, &cfg);
-        crate::color(&f, &live)
-    }
-
-    #[test]
-    fn overlapping_vregs_get_distinct_colors() {
-        // r1/r2 同时 live（ADD 前）→ 必须不同色；r3（ADD 结果）与二者不相交
-        let m = color_of(
-            vec![
-                Inst::load_const(Operand::Reg(1), 0),
-                Inst::load_const(Operand::Reg(2), 0),
-                Inst::new(OpCode::ADD, Operand::Reg(3), Operand::Reg(1), Operand::Reg(2)),
-                Inst::new(OpCode::RETURN, Operand::Reg(3), Operand::None, Operand::None),
-            ],
-            oxide_ir::ParamLayout { base: 0, count: 0 },
-            Vec::new(),
-        )
-        .unwrap();
-        assert_ne!(m.map[&1], m.map[&2], "同时 live 的 r1/r2 必须不同色");
-    }
-
-    #[test]
-    fn disjoint_live_ranges_share_color() {
-        // r1 死于 ADD0，r4 生于 ADD1——活度不相交 → 可同色
-        let m = color_of(
-            vec![
-                Inst::load_const(Operand::Reg(1), 0),
-                Inst::load_const(Operand::Reg(2), 0),
-                Inst::new(OpCode::ADD, Operand::Reg(3), Operand::Reg(1), Operand::Reg(2)),
-                Inst::load_const(Operand::Reg(4), 0),
-                Inst::load_const(Operand::Reg(5), 0),
-                Inst::new(OpCode::ADD, Operand::Reg(6), Operand::Reg(4), Operand::Reg(5)),
-                Inst::new(OpCode::RETURN, Operand::Reg(6), Operand::None, Operand::None),
-            ],
-            oxide_ir::ParamLayout { base: 0, count: 0 },
-            Vec::new(),
-        )
-        .unwrap();
-        if let (Alloc::Phys(c1), Alloc::Phys(c4)) = (m.map[&1], m.map[&4]) {
-            assert_eq!(c1, c4, "不相交活度应共享颜色");
-        } else {
-            panic!("r1/r4 应为 Phys");
-        }
-    }
-
-    #[test]
-    fn param_segment_keeps_colors() {
-        let m = color_of(
-            vec![
-                Inst::new(OpCode::ADD, Operand::Reg(3), Operand::Reg(1), Operand::Reg(2)),
-                Inst::new(OpCode::RETURN, Operand::Reg(3), Operand::None, Operand::None),
-            ],
-            oxide_ir::ParamLayout { base: 1, count: 2 },
-            Vec::new(),
-        )
-        .unwrap();
-        assert_eq!(m.map[&1], Alloc::Phys(1));
-        assert_eq!(m.map[&2], Alloc::Phys(2));
-        assert_eq!(m.map.values().filter(|&&a| a == Alloc::Phys(1)).count(), 1);
-        assert_eq!(m.map.values().filter(|&&a| a == Alloc::Phys(2)).count(), 1);
-    }
-
-    #[test]
-    fn escaped_vreg_keeps_color_and_not_spilled() {
-        let mut f = empty_function();
-        f.insts
-            .push(Inst::new(OpCode::ADD, Operand::Reg(5), Operand::Reg(3), Operand::Reg(4)));
-        f.insts
-            .push(Inst::new(OpCode::RETURN, Operand::Reg(5), Operand::None, Operand::None));
-        let mut sub = empty_function();
-        sub.insts
-            .push(Inst::new(OpCode::LOAD_VAR, Operand::Reg(9), Operand::Reg(3), Operand::None));
-        f.nested.push(sub);
-        let cfg = oxide_cfg::build_cfg(&f);
-        let live = oxide_liveness::liveness(&f, &cfg);
-        let m = crate::color(&f, &live).unwrap();
-        assert_eq!(m.map[&3], Alloc::Phys(3), "escaped 槽保持原色");
-        assert!(m.spills.iter().all(|s| s.vreg != 3), "escaped vreg 不得被 spill");
-    }
-
-    #[test]
-    fn highest_legal_color_uses_254_register_window() {
-        let mut f = empty_function();
-        f.builtin_reg_map = vec![("late".to_string(), 253)];
-        f.insts
-            .push(Inst::new(OpCode::RETURN, Operand::Reg(253), Operand::None, Operand::None));
-        let cfg = oxide_cfg::build_cfg(&f);
-        let live = oxide_liveness::liveness(&f, &cfg);
-        let map = crate::color(&f, &live).unwrap();
-        assert_eq!(map.map[&253], Alloc::Phys(253));
-        assert_eq!(map.phys_peak, 254);
-    }
-
-    #[test]
-    fn coloring_is_deterministic() {
-        let src_insts = vec![
-            Inst::new(OpCode::ADD, Operand::Reg(2), Operand::Reg(0), Operand::Reg(1)),
-            Inst::new(OpCode::RETURN, Operand::Reg(2), Operand::None, Operand::None),
-        ];
-        let a = color_of(src_insts.clone(), oxide_ir::ParamLayout { base: 0, count: 0 }, Vec::new()).unwrap();
-        let b = color_of(src_insts, oxide_ir::ParamLayout { base: 0, count: 0 }, Vec::new()).unwrap();
-        assert_eq!(a, b);
-    }
-
-    #[test]
-    fn spill_split_recolors_fresh() {
-        // 长活 L + 254 短活 B_i（每个 B_i 与 L 在同一 ADD 指令 live）：
-        // L 的 degree = 254 ≥ k=253 → kemp 卡住 → spill L → 各 def/use 点拆成单点 fresh →
-        // fresh 全部单点活度 < k → 重染色成功。这是"成功 spill"的标准场景。
-        let mut insts = Vec::new();
-        insts.push(Inst::load_const(Operand::Reg(1000), 0)); // L
-        for i in 0..254u32 {
-            insts.push(Inst::load_const(Operand::Reg(2000 + i), 0)); // B_i
-            insts.push(Inst::new(OpCode::ADD, Operand::Reg(3000 + i), Operand::Reg(2000 + i), Operand::Reg(1000)));
-        }
-        insts.push(Inst::new(OpCode::RETURN, Operand::Reg(1000), Operand::None, Operand::None));
-        let m = color_of(insts, oxide_ir::ParamLayout { base: 0, count: 0 }, Vec::new()).unwrap();
-        assert!(!m.spills.is_empty(), "长活 L 应被 spill");
-        assert!(m.spills.iter().any(|s| s.vreg == 1000), "spill 的是 L");
-        assert!(m.phys_peak <= 254, "phys_peak ≤ 254");
-        // 全部 fresh 应有 Phys 分配
-        let fresh_phys: Vec<&Alloc> = m.map.values().filter(|a| matches!(a, Alloc::Phys(_))).collect();
-        assert!(!fresh_phys.is_empty(), "fresh vreg 应着色为 Phys");
-    }
-
-    #[test]
-    fn uncolorable_returns_error() {
-        // 255 参数 CALL：nargs=255 → arg_window_base=0 → k=0 → 全部 spill → fresh 失败 → Err
-        let insts = vec![
-            Inst::call(Operand::Reg(1), Operand::Reg(2), Operand::Reg(3000), 255),
-            Inst::new(OpCode::RETURN, Operand::Reg(5), Operand::None, Operand::None),
-        ];
-        let result = color_of(insts, oxide_ir::ParamLayout { base: 0, count: 0 }, Vec::new());
-        assert!(result.is_err(), "单点活度 ≥ k 应报 Err");
-        assert!(result.unwrap_err().contains("too many registers"), "Err 消息应含 too many registers");
-    }
-}
diff --git a/crates/oxide_regalloc/tests/color_api.rs b/crates/oxide_regalloc/tests/color_api.rs
new file mode 100644
index 00000000..ef07d94b
--- /dev/null
+++ b/crates/oxide_regalloc/tests/color_api.rs
@@ -0,0 +1,156 @@
+//! 染色决策集成测试：经 crate 根 pub 入口 color() 验证选色/spill/确定性与 AllocMap 输出。
+
+use oxide_bytecode::opcode::OpCode;
+use oxide_cfg::build_cfg;
+use oxide_ir::inst::Inst;
+use oxide_ir::operand::Operand;
+use oxide_ir::{IRFunction, ParamLayout};
+use oxide_liveness::liveness;
+use oxide_regalloc::{color, Alloc, AllocMap};
+
+fn empty_function() -> IRFunction {
+    IRFunction::new()
+}
+
+fn color_of(insts: Vec<Inst>, param_layout: ParamLayout, nested: Vec<IRFunction>) -> Result<AllocMap, String> {
+    let mut f = empty_function();
+    f.insts = insts;
+    f.param_layout = param_layout;
+    f.nested = nested;
+    let cfg = build_cfg(&f);
+    let live = liveness(&f, &cfg);
+    color(&f, &live)
+}
+
+#[test]
+fn overlapping_vregs_get_distinct_colors() {
+    // r1/r2 同时 live（ADD 前）→ 必须不同色；r3（ADD 结果）与二者不相交
+    let m = color_of(
+        vec![
+            Inst::load_const(Operand::Reg(1), 0),
+            Inst::load_const(Operand::Reg(2), 0),
+            Inst::new(OpCode::ADD, Operand::Reg(3), Operand::Reg(1), Operand::Reg(2)),
+            Inst::new(OpCode::RETURN, Operand::Reg(3), Operand::None, Operand::None),
+        ],
+        ParamLayout { base: 0, count: 0 },
+        Vec::new(),
+    )
+    .unwrap();
+    assert_ne!(m.map[&1], m.map[&2], "同时 live 的 r1/r2 必须不同色");
+}
+
+#[test]
+fn disjoint_live_ranges_share_color() {
+    // r1 死于 ADD0，r4 生于 ADD1——活度不相交 → 可同色
+    let m = color_of(
+        vec![
+            Inst::load_const(Operand::Reg(1), 0),
+            Inst::load_const(Operand::Reg(2), 0),
+            Inst::new(OpCode::ADD, Operand::Reg(3), Operand::Reg(1), Operand::Reg(2)),
+            Inst::load_const(Operand::Reg(4), 0),
+            Inst::load_const(Operand::Reg(5), 0),
+            Inst::new(OpCode::ADD, Operand::Reg(6), Operand::Reg(4), Operand::Reg(5)),
+            Inst::new(OpCode::RETURN, Operand::Reg(6), Operand::None, Operand::None),
+        ],
+        ParamLayout { base: 0, count: 0 },
+        Vec::new(),
+    )
+    .unwrap();
+    if let (Alloc::Phys(c1), Alloc::Phys(c4)) = (m.map[&1], m.map[&4]) {
+        assert_eq!(c1, c4, "不相交活度应共享颜色");
+    } else {
+        panic!("r1/r4 应为 Phys");
+    }
+}
+
+#[test]
+fn param_segment_keeps_colors() {
+    let m = color_of(
+        vec![
+            Inst::new(OpCode::ADD, Operand::Reg(3), Operand::Reg(1), Operand::Reg(2)),
+            Inst::new(OpCode::RETURN, Operand::Reg(3), Operand::None, Operand::None),
+        ],
+        ParamLayout { base: 1, count: 2 },
+        Vec::new(),
+    )
+    .unwrap();
+    assert_eq!(m.map[&1], Alloc::Phys(1));
+    assert_eq!(m.map[&2], Alloc::Phys(2));
+    assert_eq!(m.map.values().filter(|&&a| a == Alloc::Phys(1)).count(), 1);
+    assert_eq!(m.map.values().filter(|&&a| a == Alloc::Phys(2)).count(), 1);
+}
+
+#[test]
+fn escaped_vreg_keeps_color_and_not_spilled() {
+    let mut f = empty_function();
+    f.insts
+        .push(Inst::new(OpCode::ADD, Operand::Reg(5), Operand::Reg(3), Operand::Reg(4)));
+    f.insts
+        .push(Inst::new(OpCode::RETURN, Operand::Reg(5), Operand::None, Operand::None));
+    let mut sub = empty_function();
+    sub.insts
+        .push(Inst::new(OpCode::LOAD_VAR, Operand::Reg(9), Operand::Reg(3), Operand::None));
+    f.nested.push(sub);
+    let cfg = build_cfg(&f);
+    let live = liveness(&f, &cfg);
+    let m = color(&f, &live).unwrap();
+    assert_eq!(m.map[&3], Alloc::Phys(3), "escaped 槽保持原色");
+    assert!(m.spills.iter().all(|s| s.vreg != 3), "escaped vreg 不得被 spill");
+}
+
+#[test]
+fn highest_legal_color_uses_254_register_window() {
+    let mut f = empty_function();
+    f.builtin_reg_map = vec![("late".to_string(), 253)];
+    f.insts
+        .push(Inst::new(OpCode::RETURN, Operand::Reg(253), Operand::None, Operand::None));
+    let cfg = build_cfg(&f);
+    let live = liveness(&f, &cfg);
+    let map = color(&f, &live).unwrap();
+    assert_eq!(map.map[&253], Alloc::Phys(253));
+    assert_eq!(map.phys_peak, 254);
+}
+
+#[test]
+fn coloring_is_deterministic() {
+    let src_insts = vec![
+        Inst::new(OpCode::ADD, Operand::Reg(2), Operand::Reg(0), Operand::Reg(1)),
+        Inst::new(OpCode::RETURN, Operand::Reg(2), Operand::None, Operand::None),
+    ];
+    let a = color_of(src_insts.clone(), ParamLayout { base: 0, count: 0 }, Vec::new()).unwrap();
+    let b = color_of(src_insts, ParamLayout { base: 0, count: 0 }, Vec::new()).unwrap();
+    assert_eq!(a, b);
+}
+
+#[test]
+fn spill_split_recolors_fresh() {
+    // 长活 L + 254 短活 B_i（每个 B_i 与 L 在同一 ADD 指令 live）：
+    // L 的 degree = 254 ≥ k=253 → kemp 卡住 → spill L → 各 def/use 点拆成单点 fresh →
+    // fresh 全部单点活度 < k → 重染色成功。这是"成功 spill"的标准场景。
+    let mut insts = Vec::new();
+    insts.push(Inst::load_const(Operand::Reg(1000), 0)); // L
+    for i in 0..254u32 {
+        insts.push(Inst::load_const(Operand::Reg(2000 + i), 0)); // B_i
+        insts.push(Inst::new(OpCode::ADD, Operand::Reg(3000 + i), Operand::Reg(2000 + i), Operand::Reg(1000)));
+    }
+    insts.push(Inst::new(OpCode::RETURN, Operand::Reg(1000), Operand::None, Operand::None));
+    let m = color_of(insts, ParamLayout { base: 0, count: 0 }, Vec::new()).unwrap();
+    assert!(!m.spills.is_empty(), "长活 L 应被 spill");
+    assert!(m.spills.iter().any(|s| s.vreg == 1000), "spill 的是 L");
+    assert!(m.phys_peak <= 254, "phys_peak ≤ 254");
+    // 全部 fresh 应有 Phys 分配
+    let fresh_phys: Vec<&Alloc> = m.map.values().filter(|a| matches!(a, Alloc::Phys(_))).collect();
+    assert!(!fresh_phys.is_empty(), "fresh vreg 应着色为 Phys");
+}
+
+#[test]
+fn uncolorable_returns_error() {
+    // 255 参数 CALL：nargs=255 → arg_window_base=0 → k=0 → 全部 spill → fresh 失败 → Err
+    let insts = vec![
+        Inst::call(Operand::Reg(1), Operand::Reg(2), Operand::Reg(3000), 255),
+        Inst::new(OpCode::RETURN, Operand::Reg(5), Operand::None, Operand::None),
+    ];
+    let result = color_of(insts, ParamLayout { base: 0, count: 0 }, Vec::new());
+    assert!(result.is_err(), "单点活度 ≥ k 应报 Err");
+    assert!(result.unwrap_err().contains("too many registers"), "Err 消息应含 too many registers");
+}