I've just installed a red bulb which comes on at night, when the regular clear bulb goes off. It's 40W and the day bulb is 60W, so the temps drop just a little.

The red bulb makes it very easy to see what he's doing at night. I'm slightly worried that he doesn't have any total darkness at any time. Should I be? Is it true that they can't see the light from the red bulb? Does it appear dark to them?