This mosaic is an interactive piece created using Flash Actionscript. A grid of buttons are activated as you rollover them looping through a set animation of expanding (light) and contracting (dark).
Each cell is given a random colour (which can be changed by clicking). This breaks up the pattern giving it an autumnal feel. (fixed amounts of red, varying levels of green).
The effect can be compared to Chameleons expanding and contracting the pours/pigment sacks around their bodies.
The autumn effect as mentioned used a fixed amount of Red and varying levels of green. Leaves turn brown because the chlorophyll (green stuff) breaks down in autumn/winter leaving behind the browny structure of the leaves (which was there anyway).
As you sway the mouse around the page, the blocks play catch-up creating dazzling watery patterns. The whole system works better on faster computers.