This is an attempt to quantify and sort in bins of a histogram a figure from my scientific paper. This figure illustrates Raman shift measurements of an area and I've been asked to build a histogram of how often do colors occur in figure. There are seven colors, each corresponding to specific Raman shift.
So first I needed to get RBG numbers, then I to reduce the number of color shades down to 7, and then count the occurences of each color.