Add Color Adjustments/Controls to Layers

Adding color adjustment options to entire layers would be incredibly helpful across many types of maps. For example, when working on a cave map, if someone needs to darken the lowest layer, they currently have to manually tweak every individual texture used. With this feature, they could simply open the Layer Settings and adjust the brightness for the whole layer at once.

This kind of tool would be useful in a wide range of maps, regardless of style, and would go a long way toward making the map-making process smoother and more efficient.