Search this site for 'flexicolor clone' the poster was stefan4u, I think. My full file of colour chems from scratch came from Maxwell Sanford, also known as MTS on this site. He sent me a large file of mix from scratch colour formulae.
The chemistry mix I presently use is Stefan's. I have even cooked up a replenisher based on it, but have yet to calibrate it rigorously to see if I am totally on the right track.