I wouldn't go for black tubes/ hull - makes it look too much like a military spec boat...might suit some on here
but not sure it would be best to attract leisure buyers.
I think yellow / grey or grey / red are distinctive colours with white hull. Depends on the effect you want. To me black is agrressive / sinister. I know its\ common but a dark blue often looks stylish (Isupposes that's why it's a common colour!)
Red / orange tube makes it look life a safety boat, many really bright colours look frivalous or plain wrong (e.g. green / turquoise IMHO).
If is a difficult balance to be head turning in the right way.
What statement are you wanting to make....brash, dependable, fun...et cand what's the target market, as that market will have buying preferences on age / income group etc...