fixer-regression-1.diff

     def _parse_value(self, val: str, maxval: int = 255) -> int:
         try:
             return int(val)
         except ValueError:
             pass
 
         if val.endswith('%'):
             val = val[:-1]
-            mult = maxval / 100
+            try:
+                return round(float(val) * maxval / 100)
+            except ValueError:
+                raise configexc.ValidationError(val, "must be a valid color value")
         else:
-            mult = maxval / 1.0
-
-        try:
-            return int(float(val) * mult)
-        except ValueError:
-            raise configexc.ValidationError(val, "must be a valid color value")
+            try:
+                return round(float(val))
+            except ValueError:
+                raise configexc.ValidationError(val, "must be a valid color value")

Error in line 22.
When input val = '1.0', representing the alpha (transparency) channel, expected output is 255, not 1.