Revert "Merge pull request #2376 from Davidster/fix_palette_readable_…

…color_contrast"

This reverts commit 6304235, reversing
changes made to 31d1d5f.

core/src/theme/palette.rs

@@ -612,19 +612,11 @@ fn mix(a: Color, b: Color, factor: f32) -> Color {
 
 fn readable(background: Color, text: Color) -> Color {
     if is_readable(background, text) {
-        return text;
-    }
-
-    let fallback = if is_dark(background) {
+        text
+    } else if is_dark(background) {
         Color::WHITE
     } else {
         Color::BLACK
-    };
-
-    if is_readable(background, fallback) {
-        fallback
-    } else {
-        fallback.inverse()
     }
 }