The default PrestaShop install offers a neutral theme, enabling sellers to quickly and freely start their activity, whatever their business line.
Nearly 2000 themes are available through the PrestaShop Addons marketplace (http://addons.prestashop.com/en/). They were created either by members of the PrestaShop community or the PrestaTeam, and are sold at reasonable prices – some are even free.
As a graphic designer/web developer, you too can put your themes up for sale on the PrestaShop Addons site, and earn 70% of the selling price.
PrestaShop also offers a complete training program for designers. Contact us through this page: http://www.prestashop.com/en/training