this is an example of the three-level coloring proposal
the colors chosen are irrelevant just to process the example
not all icons must necessarily have 2 or 3 level, in the icons in which there is no need of multiple colors, simply draw it entirely on one level, in this way, a color level is added only to the icons in which it is necessary. Doing so in the second and third color levels, the colors of the portion of icons where it is necessary color are influenced
in this way the first level influences the color of groups of icons
the second level affects only those portions of icons that need another color (for example in the mesh icon only the vertices) and so on …
in terms of design, the process in this way is also progressive, so the designer initially starts to test with the most necessary icons to have multiple colors … and if it works then a more elaborate coloring work is decided.
this is a representation of the list of categories with the three levels of color similar to the list proposed by @Evandro_Costa
these are sample portions of how the grid of icons in the 3 levels should be worked out
