Reuqirements:
1. Visibility On/Off icons are too difficult to distinguish. Probably, color-code that somehow?
1. Visibility icon should be separated from the rest of the icons set, for not to mix it.
1. If a parent of a layer is not visible, it should be easily seen. So the layer should have three states: visible, invisible (because of the parent), invisible (direclty).
1. Also note the visualization of Isolate Layer mode, atm it grays out all the layers except isolated one.
1. Color coding for layers:
1.