Minecraft wiki entry for Development_versions, associated text: Shield pattern textures now use alpha level for determining what gets the color, instead of the brightness (i.e., textures no longer store transparency as black).
Changed the unused textures for the Java Edition 1.13 menu panorama to be 1×1 pixels.
Removed textures for customized world type preset icons, except Isles.
Grass and foliage tints no longer vary within a biome, with the exception of swamps.