Fix tint

Author: willmcgugan

src/textual/filter.py

@@ -202,12 +202,13 @@ def apply(self, segments: list[Segment], background: Color) -> list[Segment]:
         _Segment = Segment
         _dim_style = dim_style
         factor = self.dim_factor
+        background_rich_color = background.rich_color
 
         return [
             (
                 _Segment(
                     segment.text,
-                    _dim_style(segment.style, background, factor),
+                    _dim_style(segment.style, background_rich_color, factor),
                     None,
                 )
                 if segment.style is not None and segment.style.dim

src/textual/renderables/tint.py

@@ -52,6 +52,7 @@ def process_segments(
         _Segment = Segment
 
         truecolor_style = ANSIToTruecolor(ansi_theme).truecolor_style
+        background_rich_color = background.rich_color
 
         NULL_STYLE = Style()
         for segment in segments:
@@ -60,7 +61,7 @@ def process_segments(
                 yield segment
             else:
                 style = (
-                    truecolor_style(style, background)
+                    truecolor_style(style, background_rich_color)
                     if style is not None
                     else NULL_STYLE
                 )