You can paint over the elastomeric with a very good 100% acrylic exterior house paint with a minimum satin sheen. Priming shouldn't be needed but consult with the maker of the latest coat of elastomeric. Each manufacture has their own recommendations for their products.
The reason why I know this is I was contracted to paint a building with a Porter elastomeric and the owner just wanted a fresh look, same color. The recommendation was wash with tsp and pressure washer, look for any peeling and spot prime raw areas with an acrylic primer then paint with a good standard house paint.