I’ve had my 3DS for a very long time now, enough to receive the 20 ambassador games from Nintendo (I don’t know if that’s a good thing or not, really). I didn’t notice until now though, that there’s quite some difference in how the GBA games are rendered, compared to their original counterparts. I can only try on a Gameboy Micro, which might not look quite the same as something like a GBA SP, which was obviously far more popular. But it should do.
I don’t think too many people had a Gameboy Micro anyway. The 3DS seems to render colors almost in the same way as the DS Lite, which means it might actually be the correct way! Considering the known issues with the original GBA and its lack of backlight, it’s possible that Nintendo made the game (which came out before the SP was launched) look more high-contrast than usual, to make it more visible in low-light conditions.
I prefer how it looks on the Micro, so it’s good to have that one extra option around. Considering how long it’s taking for GBA games to become available on the 3DS (will they ever?), most people probably won’t notice either way.