I think both Designer and Photo are amazing applications, but I find I'm using them only sparingly because of the UI colour scheme issue.
designerUK: The problem is aggravated with age (if you haven't noticed how your body changes with age, then I have to assume you are still a young person), but it's basically a scientifically proven thing that text and symbols with certain colour combinations are more difficult to comprehend than others, and this is regardless of age. There's a reason why (at least some) designers study this. If you want something to be read or understood easily and quickly, you try to make it as easy as possible for a majority of the users.