Painting the hull black?

The lapstrake hull on a Grand Banks should help conceal irregularities in the gelcoat, but as Pascal noted dark colors tend to magnify any imperfections, plus it shows every drop of salt. I'm a fan of flag blue hulls, but your wife makes a good point. My question would be... does the color justify the increased maintenance?

There shouldn't be any maintenance differences between the two but the black will show everything, water spots especially but also ANY unfairness in the hull surface, especially if your painter lays down a really smooth finish with minimal orange peel and high DOI (Depth Of Image). Many owners are surprised when repainting a gelcoat hull thinking it was smooth and fair already, the higher gloss of a good paint job often reveals "thangs" that went unnoticed.

If she's had several years of outdoor sun with the Hunter Green, she should be finished with any post cure so you likely don't have to worry about that. To help the significant expense of a repaint last to it's fullest potential I recommend you specify in your requests that she be sanded, primed, and sanded again before topcoating. Using the topcoat manufacturers primer will give you warranty coverage and a solid base the new paint can adhere to much better than scuffed gelcoat.

Go with Awlcraft 2000 so you don't have to wax it.

Hunter Green looks cool. I have a tar coating and I hate it, but it does cover up the dings from barges and docks.

If mama ain't happy, ain't nobody gonna be happy.