Hersch is my official Sonic OC. He's quite cute please take a look when you have time.
He turns from green to cyan when excited or embarrassed. Like electro from spider man.
This is based off of two things "bioluminescence" and "cyanotype", with the concept drawn more from the latter but realistically is an example of the former. Hersch is named after John Herschel, an astronomer who developed the cyanotype process in 1842.