One of the things that has been bugging me a little bit is the colored range of the marimba. Currently, the colors for range are set to this- https://i.gyazo.com/7d55596155ceca040e539596e4142898.png
The biggest problem with this is that C and E are red and A is gold. The most common size of marimba is 4.3 octave, where the lowest note is A, so the A should be default color. There are also 4.5, 4.6, and 5 octave marimbas, with notes of F, E, and C, respectively. Any note below C2 should be red, but anything from C2 to Ab2 should be yellow, and A2-C7 regular.
Any note below C2 - red
Notes from C2 to Ab2 - gold
Notes from A2 to C7 - regular
Anything above C7 - red