Map value to color scale

Question

I have a list of values which should be plotted to a map with a certain color. The plotting to the map is already done, but I need to figure out a way to map the value

Answer 1

This is one-function-only code to convert any number from any given range (let's say [0,20]) to particular color where 0 is red, 10 is yellow, 20 is green. You can use any colors and even use combination of 4 colors, so it's red - yellow - green - blue.

See the end of the gist file, where this function is used.

Gist with the code: Click here