Did that and Pokémon Red has got the Super Game Boy borders and colors, that's freakin' fantastic!
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This has nothing to do with GBC of course (and it works, even if I remove my GBC bios from the settings) but still I'm very happy to see SGB working, obviously out of the box without any BIOS files. Dunno how he made that work.
Now I'll do some tests for GBC but man ... I hope these Super Game Boy abilities are getting into the Libretro core very soon!
Edit: This is a game which has no SGB and no GBC palettes (Turtles III). Unfortunately it's black/white by default but it could be changed through options menu where you can adjust 4 different colors for the background as well as for the sprites:
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I would however love if it would just have the "standard GBC for GB palette" which appears when you put an old GB game into the GBC without pressing any direction on boot.
Edit 2: Now it's getting interesting. I tried a game which was a black cartridge (Dragon Quest Monsters). That means it can be played on GB but if put into a GBC it has full color support. This game also has a Super Game Boy border as can be seen here:
http://www.vgmuseum.com/end/gbc/a/drawarmonst-3.gif
(And I remember playing this on my SGB back in the days and it really
had that border.
But as it is a GBC game as well it "only" boots up as a GBC game in mGBA, without SGB borders.
I'll post this in the mGBA later today as well as it would be fantastic to have borders
and GBC colors at the same time if supported.
Edit 3: I posted everything in the official mGBA board
here hoping to get some exciting answers.