I recently purchased an amazing set of animated short films by the animator Al Jarnow. It was called "Celestial Navigations: The Short Films of Al Jarnow." While the set is quite varied, the majority of animated shorts deal specifically with experiments in geometry, dimension, color.
Here are two examples:
This is a similar style, but not by Jarnow:
... I find these shorts to be 'experiences' - I am deeply engrossed by the tests of shape, size, color, pattern. I wondered if anyone here could direct me to other DVD/Blu-ray sets like this or to specific animators that follow this school of design.
Feature Animation Favorites:
Tekkonkinkreet, Watership Down, A Town Called Panic, Howl's Moving Castle, Rio 2096, Mind Game, Fantastic Planet
I would highly recommend Norman McLaren: The Masters Edition. It's an 11-DVD boxed set covering the long and varied career of this experimental animated film-maker, who created a vast trove of such films for The National Film Board of Canada during his prolific career.
One of my favorites of his works is Begone Dull Care, which is drawn directly on film with a variety of techniques:
.. you can check out some of his other short films via YouTube's suggested related links.
The Image DVD set is price-y .. but comprehensive, and well-worth it for those who enjoy such films (which, admittedly, is not everyone!)
I've been a closet McLaren fan for years and have a three hour tape full of his shorts and a couple of great documentaries back from when the then more arty Channel Four used to champion animation a lot more. I was also lucky enough to catch some restored shorts as an animation companion to the Disney art exhibit in Paris and a retrospective at the Cine-Lumiere theater in London.
Really amazing works that I also should look at picking up on disc. Also check out the National Film Board of Canada's own store: they have a bunch of compilations and McLaren works, which I totally agree with Droo would be more of what you're looking for.