The look of roll20 is slick but the blue/white sometimes harshly contrasts the tone of a campaign. A few optional color schemes to set for a campaign would be fantastic. A darker scheme for a game taking place in a dungeon, or earth tones for one taking place in the wilderness. I would certainly still use the default color scheme for shorter term games like Fiasco. This would also be a great incentive to subscribe if it was a supporter only feature.