I agree that original paint adds value because the car is in original condition (assuming it's not a rusty/banged up mess with original paint). But once the original paint is bad, it is a repaint. And, the only difference is a pigment - and as @70SATMan points out, it all depends on the quality of the repaint - lots of color changes are not quality jobs. Take Sand Beige for example - to me a color change of Sand Beige brings UP the value!
