It's like a neon tube, usually blue,red, green, etc, except very low heat and lower power- usually an inverter turns your 12vdc power supply into ~200vac/~5milliamp so it doesnt need an external power source
I haven't seen white bulbs- they may exist and just aren't as widespread because who wants boring white light to mod your pc?
Im planning on using a red one and rig it to an interlock switch so that when I open the coin door it clicks on, bathing the interior in brihgt red light, plus I should be able to rig the inverter to power my LCD backlight as well