Phase 1 of the creation of life on earth was that life on earth was from nothing. Small molecules were formed from atoms of carbon and hydrogen. Earth does not have any oxygen rather it contains CO2, methane, nitrogen, hydrogen and ammonia where they were from the eruptions of volcanoes.
Somebody needs at least one XC to not be colorblind. XcY doesn't have XC, so they are colorblind. XcXC has XC, so they are not colorblind. (a colorblind female would need both to be colorblind - XcXc)
And XcXC female can pass colorblindless onto her children. For example, even if the father was a normal male (XCY), the one possible child could be XcY (with Xc from the mother and Y from the father), which doesn't have XC so its colorblind.
