>>28405117GBC games are limited to 8 palettes onscreen at once. Basically each palette is a collection of 4 colors selected by the programmer. Each 8x8-pixel tile onscreen selects one of these 8 palettes, and in that space only those 4 colors can be displayed. That's why the top left corner of the boulder is grey while the rest is brown, they were trying to make it look more colorful the only way they could.
8 bit graphics are complicated as fuck, getting anything to look decent is a challenge because of the limitations.
>>28405047I'm not even going to get into how limited the tilesets they had to work with were, but basically don't talk shit about things you know nothing about.