I think a few factors come into play.
What car is it for? What color is it now? What color will it be changed too?
By wanting to change colors, i'm assuming that originality isn't a huge concern, so if the aftermarket pieces aren't 100% accurate, it won't bother you.
How much of it will you be dying?
If it's a popular car, in a not often seen color, i might try to sell the pieces to someone restoring their car.
Like if it's a blue '71 'cuda interior.
If it's a year/model that doesn't get restored much, or wouldn't have people worrying about originality, like say a brown '73 dart interior, dye it.