Android system colors

[veloce]

Closes #560
Closes #558

• Adds a new settings entry to choose palette (only on android 12+):
• Adds a new board theme settings entry (on android 12+):
• Improve settings icons
• Improve android launcher icons, add the monochrome variant

[veloce]

I'm not sure how to make the best looking "system color" board.

The approach I used is pretty simple:

mobile/lib/src/model/settings/board_preferences.dart

Lines 208 to 209 in 82bbe4a

	final darkSquare = Color(corePalette.primary.get(70));
	final lightSquare = Color(corePalette.secondary.get(90));

It uses dimmed version of primary and secondary colors. There is maybe a way to improve that?

[LSeelig]

It uses dimmed version of primary and secondary colors. There is maybe a way to improve that?

I am no expert, but from looking at the other board themes, I think it needs a lot more contrast. Both darker dark squares and lighter light squares.

You might also want to use the fixed color (see primary fixed and 'on primary fixed/variant' so the light/dark squares don't get inverted by switching between light and dark theme.

https://m3.material.io/styles/color/system/how-the-system-works

[veloce]

This is the best I could come up with.

The system color board looks nice with all the different wallpaper I tried, in my opinion.

For now I don't think I'll make it the default. I'm a bit reluctant because of the strong identify of the lichess brown board, and also because with the system colors the last move and selected square are not as much visible as with the stock boards.

The option to switch to system colors is quite visible in the settings screen so people who like that feature would find it easily.

[LSeelig]

I like it alot. Might be open to future tweaks of the square highlight, though I don't know how I would make it better yet.

[LSeelig]

I dug into the current themes. This purple theme is fairly similar my system color pallette. Square highlights are in shades of green, despite the purple squares. Could you get better contrast if you weren't trying to theme the highlights?

[veloce]

I have to theme the highlights, because I have to ensure the highlights are visible in any case. If I keep the default green highlights they won't be visible with green themes.

[veloce]

It's good to have a default system colors board, but you'll always get a better result with stock boards I think. That's why I let the users choose another board theme, even if they activate system colors. In your case you'd choose to use pink board with system palette to have the best out of it (here the board is an image and there's a diagonal shadow on each square).

[LSeelig]

Understood. I think your end result is excellent and agree w.r.t. user choice.