To answer the question about colours...YES they come in many colours.
In fact I purchsded some round lights to replace my old ones in my 85 Stinger and they have two colours in them. If you flick the switch one way they are blue. If the switch is flicked the other way they are red. They were not cheap however at almost sixty bucks per. I bought six for my boat.
The amperage draw is amost non existant and they do not get hot like the old twelve volt 1156 style bulbs. Holy Cow!!! reading a book at night almost made the pages start on fire! Those bulbs get damn hot!
That is another reason why I changed them out.