The different elements of layers and channels are represented by
different icons. Each icon has four different varieties
representing that element in it's default state (grey), in use
(yellow), default and currently being copied (low cyan), and in use and
being copied (bright cyan).
HSL isolation key (qualifiers)
Shape isolation
Lift-Gamma-Gain primary
correction
RGB Bezier curve-based correction
HSL output correction
Six vector (cube-based) channels
In COPY or READ mode, clicking on the icons will toggle them between
the copy event (low-cyan/cyan) and the list event (grey/yellow).
