I suggest you look at https://www.mathworks.com/matlabcentral/fileexchange/69470-custom-colormap for the creation of the colormap given offsets and RGB information. That code can build color gradients -- though in your case I see that the colors are constant for each block.
I can see bins that are 61 values wide, and others that are 88, or 231 ... nothing that is nicely divisible into chunks. So you are pretty much going to need a colormap that is 30048 entries.
It is possible that your system cannot handle colormaps that are more than about 16384 entries; it might be necessary to fudge the boundaries a bit. For example if you rounded all the boundaries to even, then you could get away with half as many colormap entries.
