They're regional, IIRC . . .
Northern fish wear the purple stripes on their lateral lines, while fish from more southerly parts of the range are decked out in a more solid violet with scattered pinkish scales. Some writers regard only the striped fish as the true C. lubbocki, and suggest that the southern fish should be given a new name.
There'll be a color change as individuals go from juvenile to female to male as well, but that's unrelated.
~B.