Unused pixels in colormap textures

May relate to MC-159560.

The bug

Color map textures will always pick from the bottom-left half of the texture file, including the central falling diagonal. This means that the entire top-right half of the texture goes completely unused by the game. Despite this, it is still colored in, particularly in the case of the foliage map.

How to fix

Remove all of the pixels from the top-right half of each colormap texture. I've included a fixed copy each for the grass, foliage and water (see MC-239129) color maps.