diff --git a/CHANGES.rst b/CHANGES.rst
index c3e60acff..55eabefd4 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -5,6 +5,9 @@ Changelog (Pillow)
 9.3.0 (unreleased)
 ------------------
 
+- Raise an error when allocating translucent color to RGB palette #6654
+  [jsbueno, radarhere]
+
 - Added reading of TIFF child images #6569
   [radarhere]
 
diff --git a/Tests/test_image_access.py b/Tests/test_image_access.py
index bb09a7708..a000cb64c 100644
--- a/Tests/test_image_access.py
+++ b/Tests/test_image_access.py
@@ -345,13 +345,14 @@ class TestCffi(AccessTest):
 
     @pytest.mark.parametrize("mode", ("P", "PA"))
     def test_p_putpixel_rgb_rgba(self, mode):
-        for color in [(255, 0, 0), (255, 0, 0, 127)]:
+        for color in ((255, 0, 0), (255, 0, 0, 127 if mode == "PA" else 255)):
             im = Image.new(mode, (1, 1))
             access = PyAccess.new(im, False)
             access.putpixel((0, 0), color)
 
-            alpha = color[3] if len(color) == 4 and mode == "PA" else 255
-            assert im.convert("RGBA").getpixel((0, 0)) == (255, 0, 0, alpha)
+            if len(color) == 3:
+                color += (255,)
+            assert im.convert("RGBA").getpixel((0, 0)) == color
 
 
 class TestImagePutPixelError(AccessTest):
diff --git a/Tests/test_imagepalette.py b/Tests/test_imagepalette.py
index 475d249ed..5bda28117 100644
--- a/Tests/test_imagepalette.py
+++ b/Tests/test_imagepalette.py
@@ -50,6 +50,16 @@ def test_getcolor():
         palette.getcolor("unknown")
 
 
+def test_getcolor_rgba_color_rgb_palette():
+    palette = ImagePalette.ImagePalette("RGB")
+
+    # Opaque RGBA colors are converted
+    assert palette.getcolor((0, 0, 0, 255)) == palette.getcolor((0, 0, 0))
+
+    with pytest.raises(ValueError):
+        palette.getcolor((0, 0, 0, 128))
+
+
 @pytest.mark.parametrize(
     "index, palette",
     [
diff --git a/src/PIL/ImageFont.py b/src/PIL/ImageFont.py
index 8be7f0f10..b3a7cdb98 100644
--- a/src/PIL/ImageFont.py
+++ b/src/PIL/ImageFont.py
@@ -955,6 +955,11 @@ def truetype(font=None, size=10, index=0, encoding="", layout_engine=None):
                      encoding of any text provided in subsequent operations.
     :param layout_engine: Which layout engine to use, if available:
                      :data:`.ImageFont.Layout.BASIC` or :data:`.ImageFont.Layout.RAQM`.
+                     If it is available, Raqm layout will be used by default.
+                     Otherwise, basic layout will be used.
+
+                     Raqm layout is recommended for all non-English text. If Raqm layout
+                     is not required, basic layout will have better performance.
 
                      You can check support for Raqm layout using
                      :py:func:`PIL.features.check_feature` with ``feature="raqm"``.
diff --git a/src/PIL/ImagePalette.py b/src/PIL/ImagePalette.py
index b73b2cd9d..fe76c86f4 100644
--- a/src/PIL/ImagePalette.py
+++ b/src/PIL/ImagePalette.py
@@ -115,7 +115,11 @@ class ImagePalette:
             raise ValueError("palette contains raw palette data")
         if isinstance(color, tuple):
             if self.mode == "RGB":
-                if len(color) == 4 and color[3] == 255:
+                if len(color) == 4:
+                    if color[3] != 255:
+                        raise ValueError(
+                            "cannot add non-opaque RGBA color to RGB palette"
+                        )
                     color = color[:3]
             elif self.mode == "RGBA":
                 if len(color) == 3:
diff --git a/winbuild/build_prepare.py b/winbuild/build_prepare.py
index f4515468f..ad7b1ddb6 100644
--- a/winbuild/build_prepare.py
+++ b/winbuild/build_prepare.py
@@ -281,9 +281,9 @@ deps = {
         "libs": [r"imagequant.lib"],
     },
     "harfbuzz": {
-        "url": "https://github.com/harfbuzz/harfbuzz/archive/5.2.0.zip",
-        "filename": "harfbuzz-5.2.0.zip",
-        "dir": "harfbuzz-5.2.0",
+        "url": "https://github.com/harfbuzz/harfbuzz/archive/5.3.0.zip",
+        "filename": "harfbuzz-5.3.0.zip",
+        "dir": "harfbuzz-5.3.0",
         "build": [
             cmd_cmake("-DHB_HAVE_FREETYPE:BOOL=TRUE"),
             cmd_nmake(target="clean"),