Add: Colour Palette Revisions

[ghost]

• Add "Super Game Boy" bios palettes to Gambatte

• Include additional default SGB palette selections found in Nintendo Power magazine

• Create an "optimal" option that will default to the more colourful option between a game's default GBC and SGB palette

• change the default colour output to be "true colour". Leave Gambatte's (or any other desired) colour correction to shaders instead.

[AreaZR]

@MaddTheSane any thoughts?

[ghost]

@AtariDreams @MaddTheSane I forgot I even had this PR open. Thanks for the merge!

I don't know how realistic this is, but it might be better if it wasn't merged in as-is? As you can see from the frequency of commits, I rethink and tweak this often for personal use. And there's stuff in here now that wasn't there when I first opened the PR and maybe it doesn't make a lot of sense now (fan palettes from deviantart, a palette for a romhack, unused palettes based on BGB, etc.)?

You're welcome to adapt parts that make sense to keep. But I kind of think it shouldn't all be there now in full.

[clobber]

Yeah I agree - reverting now.

[stuartcarnie]

Is it worth considering loading custom palettes as a user feature? I know Commodore 64 emulators like VICE, Frodo and virtual64 all support custom palettes.