This is a KarelContest submission for the Aesthetic merit category.
Karel lives in a 21x21 world and operates at full-speed, starting in the
lower left, facing east. Karel is an artist. Within his 21x21 world,
Karel likes to explore the shades of color across the rainbow, from
White-Gray-Black to ROYGBIV (red-orange-yellow-green-blue-indigo-violet).
He initially seeks the center of his plain world and proceeds to paint
it. First, he paints his entire world different shades of a single color
and alternates through the 8 colors. He expands out and returns back
in following the perimeters. However, this is not vibrant enough. Next,
he paints his world in shades of all 8 colors at once, swirling
counterclockwise. Finally, he repeats this at twice the speed, creating
flashes of color. After this, he is so tired that he blacks out
(literally) and rests in the upper-right square.