Higher temps generally mean a speed up in the metabolism of the organism, thus higher growth rates. Some folks would kill to have their tanks stay as low as yours. I personally like my tank to stay closer to 80 degrees and have run my tank as high as 84 degrees. But I am probably in the minority of all reefers.
More light = more color usually. Raise the coral higher in the tank, just dont shock it by going immediately from low light to maximum light.