Law of Commonality

When we bought our car, we picked the color metallic aspen green with the thought that it was most uncommon color we'd seen on the roads; but now we seem to find that every other car has that color! Is it that every other car is of that color or is it that we seem to be looking at only those cars which have the same color? Doesn't it happen to everybody with some thing or the other other? I think it's because we can relate to that 'thing'. Earlier had we heard/seen such a 'thing' we'd have probably ignored it because it doesn't mean anything to us; but now that we possess it, we pay special attention it.