I was sort of in the same camp as the OP at first glance of the class, not too impressed with the color scheme/pondering possible placeholder graphics, HOWEVER after a few more watches of both the Picto in game vid and the Full trailer vid I have an oddly sneaking suspicion that possibly, just possibly, the particular paint style used is due to an interesting effect that MIGHT occur in the dark/at night.

Since we only have full day in game footage to observe and Krile's display is at night, I am wondering if the paint in fact does glow brightly in the dark similar to Krile's nighttime display. I posit that as a theory due to the end of Krile's display in the Full trailer when Night becomes Day and it appears the paint stops glowing. The coding might need to be a paler paint to pull off a change to a bright glow at night. If you observe the paint in the in game play footage the paint is singular colored with a lighter/white contrasting paint. They may not be using Deeper/Darker hues due to the change from matte to glow during a change of Day to Night or Lit to Darkness.

Just a random thought.