You can change the light flashing pattern by clicking a different button within the control panel.

Each Light Individually causes each light to flash at its own rate, as if it had its own internal timer.

All Lights In Unison causes all the lights to turn on and off at the same time, as if one timer controlled all the lights.

Light Chase causes the lights to “chase” each other across the screen.

Xmas Light Chaos causes a light to change to a different color every time it flashes — try doing that with real Christmas tree lights!

All Patterns, In Sequence displays each of the patterns above, in order,  for 30 seconds at a time.

Unplugged stops the lights from flashing, speeding up your computer if the lights are slowing down a program. Xmas Lights doesn’t noticeably slow down most applications, but for time-intensive tasks involving no typing (such as video games), Xmas Lights can have trouble detecting how much “spare” computer power is available to flash the lights.

Since Xmas Lights does all its work in your Mac’s spare time, All Lights In Unison and Light Chase may not look realistic on slower Macintoshes because the lights aren’t drawn fast enough; if that’s the case, try using one of the other patterns.