This is a simple application (NOT add-on) that can "convert" a png image to a colorset and back again.
Links:png2colorset
PE Sourcecolorset2png
PE SourceReadme:png2colorset takes input on the CLI, asking for source image name and the headers for each column and then writes the output to "colorSet.txt". colorset2png is fully automatic and takes the file "colorSet.txt" and makes an image called "colorSet.png".
Example:This is an enlarged version of the colorset2png from BAC's bucket (because I had that one nearby):
Important notice:This is NOT an add-on. Once again, this is NOT an add-on.
Also, if the colorset isn't a perfect rectangle then png2colorset will break. You have been warned.