Chaos Rush recently posted on the Romhacking.Net forums about a color restoration patch for the MOTHER 1 side of MOTHER 1+2 on the GBA:
As some of you may know, a lot of GBA games have brightened, washed out colors in order to make it easier to see on an unlit GBA. This is a patch for *Mother 1+2* for GBA that restores the colors back to what they were on NES (just the Mother 1 side of the ROM, I have not bothered with the Mother 2 side and don’t have any plans to)
…except I’ve made several patches. Because there are no true NES colors because of the way it handles colors. To my knowledge, NES games don’t have any palette data, they just have ‘color assignments’ choosing from the NES’s 64 different color ‘slots’. But the way these colors appear can be different from one TV to another, whether it’s between NTSC and PAL, or RF/AV cables… so really there are no ‘true’ NES palettes. Which is why I made two patches, one patch using a supposedly ‘accurate’ NES palette I found on a NES dev forum, and another patch using the palette that Nintendo uses for NES Virtual Console games on Wii & Wii U (credit to SuperrSonic and Daxtsu from GBAtemp for ripping the VC palette).
When they ported Mother 1 to the GBA, they adapted the NES 64 color limit to it, and came up with their own unique color palette that was clearly optimized for the original model GBA and nothing else. Unfortunately that palette they used makes trees look neon-green on backlit displays.
There’s a lot more to read about this patch, so if you’d like to learn more or want to download the latest patch, head over here!