>>12381393You obviously have never programmed on a GB/GBC before.
The background is a single layer made up of 8x8 pixel tiles. Each tile can select only one of eight distinct palettes. Since G/S were compatible with the original GB, all 8 palettes were monochrome to avoid having to make separate tilesets for the GB (keep in mind the cartridge was only 2MB).
The only alternative they had was to put a grass tile in the upper-left corner, which would make it look even more jagged.
