I read you do a paint suitable for painting over cement finishes? (Exterior) I don't know where to start looking on your website? Also, can patio garden stones be painted, and will it stay on for long, is it weather resistant?
Assuming you are looking to paint an external building wall with cement based render you could consider Wethertex AP77 Flexible Smooth Masonry Paint - New Colours.
This is available mixed to many RAL, NCS or BS colours in a matt finish.
Regarding patio stones, we would need more information and pictures of the area to be sent to [email protected] to see if we can offer a product for this application.