I think the ability to tint items (textures, tokens, everything else) and the whole map is a very vital tool that is missing from the editor.
With the ability to tint items we could create multiple variants on the same token, item, textures, anything.
The ability to tint the map/tabletop is a must as it allows us to set the mood. We could tint it blue to set the map as night, green/grey for a hazy swamp, dark red for hell, etc.
Oh, and the ability to save these tints is a *must* so we can tint things on the fly.