Tweak dynamic theme dominant color detection

Currently, a lot of manga have the same whit/black-ish background color, which results of the thumbnails containing a lot of white/black colors.
These changes improve this a little

- reduce impact of white and black colors
- use "precision" mode of algorithm

src/modules/manga/components/MangaDetails.tsx

@@ -189,7 +189,14 @@ const Thumbnail = ({
         img.onload = () => {
             Promise.all([
                 Vibrant.from(img).getPalette(),
-                new FastAverageColor().getColorAsync(img, { algorithm: 'dominant' }),
+                new FastAverageColor().getColorAsync(img, {
+                    algorithm: 'dominant',
+                    mode: 'precision',
+                    ignoredColor: [
+                        [255, 255, 255, 255, 75],
+                        [0, 0, 0, 255, 75],
+                    ],
+                }),
             ]).then(([palette, averageColor]) => {
                 if (
                     !palette.Vibrant ||