I wanted to say “please can we customize the thresholds for each color ?”
(minimal useful feature : let me set n such that green is buffer>n ;
maximal feature = let me add more colors at arbitrary thresholds)
I did a search in the forum and ended here, which seems like a reasonable place to ask 
I figured this must have been asked for a million times but I can’t find them synonym threads. This other thread was another candidate.