While not game breaking, this is a super annoying visual bug that its not uncommon at all while playing. Sometimes, the grass color on the side of grass blocks does not match the color on the top of the grass block. This is especially apparent in biome transitions (although not limited to), like in between the swamp and plains biomes, for example. It also randomly occurs in normal biomes even if it isn't in a biome transition. I have seen up to 3 or 4 different colors in the same general area on the sides of grass blocks! I'm pretty sure this affects more than just android, but I can't test that right now. This affects normal vanilla minecraft, as well as resource packs. I have yet to see a resource pack that can fix this issue, and it seems the only solution is a fix in the actual game code. This also could affect other color changing blocks, like leaves, but I haven't noticed if that is the case. I have lots of screenshots of the issue. Some screenshots are vanilla minecraft, without any applied resource packs, and others I have applied a resource pack with full grass sides because it shows the problem a lot clearer. Please note that it still affects vanilla minecraft, and is NOT limited to resource packs. Also note that I've seen this affecting multiple other biomes, not just the swamp, plains, and forest.
I have searched through the issue database to see if there were any reported issues like this already, but could not find any, so I don't think this is a duplicate.