diff --git a/Tests/test_image.py b/Tests/test_image.py
index 0fe5d3c807d..243126a9f35 100644
--- a/Tests/test_image.py
+++ b/Tests/test_image.py
@@ -671,7 +671,7 @@ def test_remap_palette(self) -> None:
         assert_image_equal(im_p, im_remapped)
         assert im_p.palette is not None
         assert im_remapped.palette is not None
-        assert im_p.palette.palette == im_remapped.palette.palette
+        assert bytes(im_p.palette.palette) == im_remapped.palette.palette
 
         # Test illegal image mode
         with hopper() as im_hopper:
diff --git a/src/PIL/FliImagePlugin.py b/src/PIL/FliImagePlugin.py
index 99d6be1df6d..1749d0668a4 100644
--- a/src/PIL/FliImagePlugin.py
+++ b/src/PIL/FliImagePlugin.py
@@ -23,7 +23,6 @@
 from . import Image, ImageFile, ImagePalette
 from ._binary import i16le as i16
 from ._binary import i32le as i32
-from ._binary import o8
 from ._util import DeferredError
 
 #
@@ -104,9 +103,7 @@ def _open(self) -> None:
                 if not chunk_size:
                     break
 
-        self.palette = ImagePalette.raw(
-            "RGB", b"".join(o8(r) + o8(g) + o8(b) for (r, g, b) in palette)
-        )
+        self.palette = ImagePalette.raw("RGB", tuple(v for rgb in palette for v in rgb))
 
         # set things up to decode first frame
         self.__frame = -1
diff --git a/src/PIL/Image.py b/src/PIL/Image.py
index 82e71035787..dcbc904fe92 100644
--- a/src/PIL/Image.py
+++ b/src/PIL/Image.py
@@ -2167,8 +2167,6 @@ def putpalette(
                 palette = ImagePalette.ImagePalette(palette=data.palette)
                 palette.dirty = 1
         else:
-            if not isinstance(data, bytes):
-                data = bytes(data)
             palette = ImagePalette.raw(rawmode, data)
         self._mode = "PA" if "A" in self.mode else "P"
         self.palette = palette
@@ -2176,8 +2174,6 @@ def putpalette(
             self.palette.mode = "CMYK"
         elif "A" in rawmode:
             self.palette.mode = "RGBA"
-        else:
-            self.palette.mode = "RGB"
         self.load()  # install new palette
 
     def putpixel(
diff --git a/src/PIL/TiffImagePlugin.py b/src/PIL/TiffImagePlugin.py
index 42c1cc96c1e..2ee99f097b3 100644
--- a/src/PIL/TiffImagePlugin.py
+++ b/src/PIL/TiffImagePlugin.py
@@ -65,7 +65,6 @@
 from . import ExifTags, Image, ImageFile, ImageOps, ImagePalette, TiffTags
 from ._binary import i16be as i16
 from ._binary import i32be as i32
-from ._binary import o8
 from ._util import DeferredError, is_path
 from .TiffTags import TYPES
 
@@ -1679,8 +1678,8 @@ def _setup(self) -> None:
         # fixup palette descriptor
 
         if self.mode in ["P", "PA"]:
-            palette = [o8(b // 256) for b in self.tag_v2[COLORMAP]]
-            self.palette = ImagePalette.raw("RGB;L", b"".join(palette))
+            palette = tuple(b // 256 for b in self.tag_v2[COLORMAP])
+            self.palette = ImagePalette.raw("RGB;L", palette)
         else:
             self.palette = None