First commit, it reads the fan's rps every 10 seconds and sets the flash fps at the same rate.
It finally produces the secondary colors in one of the possible configurations, the speed of the flashes is computed at button press and can be slightly modified at the same moment with the potentiometer.
Clean version, also seems to work much better now that the lecture of the potentiometer is done almost continuously, so it can also be turned if need be.
Final comments in code
Merge branch 'master' of https://github.com/vichango/color-wheel