Recently, we added to our map service -https://www.maptiler.com/maps/#streets//vector/3/-74/40.73 an ability to completely change the map design in just a few clicks. You pick five colors and the rest of the map change accordingly. It is very handful for anyone who wants a map fitting web or mobile app design.
Pro users have an advanced tool where they can design every single map property, add own geographical layer or switch on/off individual map components (like POIs or landcover).
Apart from colors, users can change fonts or one of 55 languages.
The full blog post is at https://www.maptiler.com/blog/2018/09/design-own-map-with-five-clicks.html , you can try the functionality with a free personal account.