I totally get what you are saying about wanting the boat in a different color. On mine, the decks were some light turquois in color, and a previous owner had painted them a nice dark red. I think it might have even been several owners back.
The same person painted the inside of the hull (I know, because they handed down receipts). If the boat had been the original color, I would probably not have looked at it - I couldn't picture myself in what must have looked like the inside of a pool.
The paint was a reputable marine brand. (I'm not giving a name, because I know that the particular type paint is no longer for sale). The looks are still pleasing even though after over a decade since appliation, the paint has faded were it was uncovered for several seasons and any and all scratches look bright blue-green - exposing a gel coat in good shape where the paint has rubbed off.
I'm still likely to repaint, when it comes to that.
Inside of the hull was painted with the same brand, light gray. Has held up, except below the floorboards (standing water at times and rubbing of the boards' feet on the paint). I protected the laminate with a touchup of clear gelcoat repair paste. (Don't really care about the looks under the floors one way or another, as long as there's no exposed laminate

)
The paint on the outside of the hull is a different story. It's the same shade as the gelcoat, and looks like it's been applied in order to hide extensive gelcoat cracking. I don't know what kind of paint it is, but it's held on tenaciously, also for nearly a decade (if not longer). It's survived rounds of pressure washing by eager teenage helpers, and is damaged only where I've beached the boat or banged it into the trailer on retrieval.
My conclusion is that I would definitely go for high-grade marine paint, if and when I get around to repainting the bottom.
(My DS is sailed dry, that helps a lot with the durability of the paint, and the sun exposure is moderate)