Well, to get you noticed obviously as bright a colour as possible is gunna do the trick, but if your looking for sponsorship then i'd stay clear of the gulf colour scheme, as it may clash with sponsors logo's and it leaves less panel space for big stickers. A white car would be best for making simple graphics stand out, and easy to paint if you stuff it, or to touch up slight stone chips or tyre donughts!
What series is it your racing in?
Also if you have any ideas of prospective sponsers, then you should probably go for a colour that suits their graphics/logos.