Definitely blue hulls or coloured hulls fade and look chalky after only a few seasons if exposed to strong sunlight. This is not so much with the vertical parts of the hull but with the parts that are angled upwards, the aft haunches for example. You can see plenty of examples of this in any Med marina. Also coloured hulls look much worse than white hulls if scratched or damaged because the white grp is often exposed below the coloured gelcoat and it's very obvious where the damage is. Coloured hulls look fab IMHO but they definitely need more looking after