Here we see Marcellus painting in his attic studio. The artwork, created by Lego and supplied with the Parisian Restaurant set, is hilarious. You might think, of course, that if you are painting in Lego, your options are limited to squares and rectangles. But, as we will later discover, this is only one of Marcellus' styles.
From a grammar point of view, I really enjoy the variis coloribus ablative of description. And the way it rolls nicely off the tongue.
Marcellus is painting inside. Marcellus is painting squares and rectangles of various colours. As I said, it pleases Marcellus greatly to paint.