It's a common myth that classical marble statues were pure white and boring. In fact it's modern consensus that they were very often skilfully painted, but the colours were lost to time.
Augustus looking very fine there.
Source (in Spanish): http://rodrigorivas3d.blogspot.com/2014/05/policromia-en-la-antiguedad.html
Yeah haha, the bright colors and extravagance kinda makes it look like the boy version of la virgen de Guadalupe too