It's best for them not to have any light at all at night, even if it's colored; it disturbs their sleep. As long as the temperature stays above 65 F, you don't need any extra heat or light, but if it gets colder than that you should use a ceramic heat emitter (heat but no light).
Yes, no light emitting heat source at night, they like it cool and pitch dark. This allows their metabolism to slow down so they can actually get rest. Disturbing their sleep patterns will cause loss of appetite, lethargy and, a generally grumpy attitude.