The coloring could be used for a much better info. Who really cares what tree a skill comes from. Especially since it is already shown through the sectors of the skill wheel. 


Therefore: Get rid of the redundant color-code info, and make use of that info-channel for communicating more relevant info. For example, I would assume that people either make a system or a fleet hero, but rarely both. So dividing the skills in these 2 areas would probably make much more sense.