I have Sand with Seal (which, judging by a Meteor car in the showroom is *very* similar, though couldn't tell what it'd be like in sunlight).

I've had 30k with the Sand full-leather since May 05. It does get dirty, but not rapidly (I've only cleaned fully once, and that was as much to feed the leather as to clean it). It's not like you have to clean it every month or anything.

The main issues I have found are that scuffs tend to show white, so (while not critical) I'd try to be careful not to clean too vigourously (particularly near the stiching) or drag heavy items over the leather.
But if you're careful, I don't think it's any more of a problem than any other colour.

I saw a used example, newer than mine and with less miles in the showroom, and the leather was out of condition and rather creased - mine looked in much better nick. So I guess if you look after the leather with care, it'll maintain it's looks better.

Have you considered cocoa? It does look good, and is dark enough to hide dirt.