Use round()

Author: radarhere

Tests/test_imagecolor.py

@@ -200,7 +200,7 @@ def test_color_hsv() -> None:
 
 
 @pytest.mark.parametrize("mode, premultiplied_mode", (("LA", "La"), ("RGBA", "RGBa")))
-@pytest.mark.parametrize("color", ("#f00", "#ff000080"))
+@pytest.mark.parametrize("color", ("#f00", "#ff000080", "#ff000050"))
 def test_color_premultiplied_alpha(
     mode: str, premultiplied_mode: str, color: str
 ) -> None:

src/PIL/ImageColor.py

@@ -161,8 +161,7 @@ def getcolor(color: str, mode: str) -> int | tuple[int, ...]:
     else:
         value = rgb
     if mode[-1] == "a":
-        # Rounded, to match convert()'s premultiplication.
-        value = tuple((band * alpha + 127) // 255 for band in value)
+        value = tuple(round(band * alpha / 255) for band in value)
     if mode[-1] in ("A", "a"):
         return value + (alpha,)
     return value[0] if len(value) == 1 else value