Have had many different cars over the years but never a black one, definitely has to be washed religiously. Darkest one I ever had was a dark blue '78 Mercury Monarch, that paint was Horrible. When you washed & waxed it, you'd come away with Blue rags! The paint was just oxidizing that bad. Thankfully it was a Fleet vehicle and I didn't keep it more than 2 years. Had 2 white cars in other years but found they looked almost as bad when dirty. I was in Auto Appraisal for some time and both Silver & Gold seem to hide minor scratches and such the best.
What counts to me the most is the Interior color since you're going to be IN there more than looking at the outside. Unfortunately so many color choices stick you with either Gray or Black on the inside and I've had enough of those that I won't have it anymore. Over the years I've decided that Beige feels the most comfortable to me. My current vehicle has a beige interior with woodgrain accents and the exterior is a light greenish hue which I feel is kind of a classy looking combination.