I never saw Majora's Mask as having this amazing art style anyway, so having it be less gloomy really isn't a deal-breaker at all for me. Some games have indispensable art style and graphics, like Bastion, Limbo, Okami; those games, if changed in a remake, I'd be quite disappointed with. Majora's Mask, not so much. So I'm completely indifferent to this change, it matters not!