Well, very little of San Diego is desert. But you guys knew that, right?
However, your point about the seasonality of San Diego is an interesting one. What interests me is that I wonder if growing up in that kind of place contributed to my feeling that colors aren't seasonal. I wouldn't say San Diego is seasonless, just more subtle compared to other places. In any case, I can see how the peculiarity of it's seasons might change a person's perceptions on the matter.