As long as it's getting its 60 FPS, each rotation is a second.
(there's currently no check against the system clock)

A clock would be pretty straight forward.

right now I just have the r,g,b values (0-255) and I vary each one for some random value between -10 and 10 (I was thinking about seeing if "inertia" would be interesting for that as well but decided to keep it closer to my first dream thought)

I could think of a different behaviours for the minute and hour ring...
have them just like the seconds ring, but slower, each with its own rgb - probably too tough to read
have them pick up the current color of the seconds ring - also probably tough to read

have them constantly "flashing" to the current color of the seconds ring at their current position only

WDYT?

heh, that "dirty gray" is kind of a signature color of processing, I think it's the default, #CCCCCC

I think I'm leaving it as is, out of a severe bit of lazy (also I can't think of a great way of advancing the hour hand w/o having to store and redraw everything else.)