diff --git a/Tests/test_imagepalette.py b/Tests/test_imagepalette.py
index 3f37c23c5ae..da0f652df00 100644
--- a/Tests/test_imagepalette.py
+++ b/Tests/test_imagepalette.py
@@ -15,6 +15,20 @@ def test_sanity() -> None:
     assert len(palette.colors) == 256
 
 
+def test_colors_rawmode() -> None:
+    palette = ImagePalette.raw(
+        "BGRX",
+        (0, 0, 0, 0, 255, 255, 255, 0, 0, 0, 255, 0, 0, 255, 0, 0, 255, 0, 0, 0),
+    )
+    assert palette.colors == {
+        (0, 0, 0): 0,
+        (255, 255, 255): 1,
+        (255, 0, 0): 2,
+        (0, 255, 0): 3,
+        (0, 0, 255): 4,
+    }
+
+
 def test_reload() -> None:
     with Image.open("Tests/images/hopper.gif") as im:
         original = im.copy()
diff --git a/src/PIL/ImagePalette.py b/src/PIL/ImagePalette.py
index 03fb4d8c4a4..1d4a2f04bb8 100644
--- a/src/PIL/ImagePalette.py
+++ b/src/PIL/ImagePalette.py
@@ -62,10 +62,18 @@ def palette(self, palette: Sequence[int] | bytes | bytearray) -> None:
     @property
     def colors(self) -> dict[tuple[int, ...], int]:
         if self._colors is None:
+            palette = self.palette
+            if self.rawmode:
+                from . import Image
+
+                im = Image.core.new("P", (0, 0))
+                im.putpalette(self.mode, self.rawmode, bytes(palette))
+                palette = im.getpalette(self.mode, self.mode)
+
             mode_len = len(self.mode)
             self._colors = {}
-            for i in range(0, len(self.palette), mode_len):
-                color = tuple(self.palette[i : i + mode_len])
+            for i in range(0, len(palette), mode_len):
+                color = tuple(palette[i : i + mode_len])
                 if color in self._colors:
                     continue
                 self._colors[color] = i // mode_len