I dunno man, there seems to be a bit too much going on to fit the "Less is more" theme. It's a great piece of work, but it seems a bit too frenzied for this kind of application. I'd love to see this in a different context than on a T-shirt though!
It does have a very Mondriaan feel, especially if it were on a white tee. I really like it! There's a really subtle complexity in the way you've arranged the boxes.
About my design
on black or grey
simple design elements
with dynamic movement
less is more