Please replace rainbow color map - it has become a bad taste within academic environment because rainbow colors can't be perceived linearly and so there had been invented meaningful colors maps

See paper "Why We Use Bad Color Maps and What You Can Do About It" by Kenneth Moreland

Also, matplotlib has got great article about custom color maps you can use out of the box along with rationale

True story! I came across this course to find inspiration on how to improve a control of a human animation neural network model for a game development domain: 3 control variables, 150 DOF state and a neural network with ~2 millions of weights.