1) If two colours are selected, there is no difference in the order of mixing. (Red + Blue = Blue + Red)
2) Each colour is its own identity. (Red + Red = Red)
3) For all generations after GEN-1, no colour created in their respective generation can be mixed until the next iteration.
(Orange, Purple, Green are created in GEN-2; thus, they cannot mix until forming GEN-3)
Determine the number of colours in the set GEN-6 (after mixing).