Posted 6/22/2020 16:05 (#8329722 - in reply to #8328655) Subject: RE: Concrete paver discolouration.
I installed Pavers for 6 yrs. Mostly Techo Bloc made in Canada and sold in the states. We were instructed to prepare our "base" with crush and run that was tamped with a machine to a concrete like stiffness. Then we used "concrete" sand - very course- as the bedding for the pavers. We would use 3/4" black iron pipe (it is 1" outer diameter) as screed rails. Place them on the outside edges of the area to be paved. fill the field area with sand and screed along giving you a nice flat 1" thick bed of sand to lay your pavers in. then when you are finishing your pavers make sure you use polymeric sand to fill the joints. it has a water activated glue that will help it to stick, locking the entire surface together and helping to prevent weeds from growing.
As for the discoloration, it is water and minerals that have been absorbed into the pavers. It may or may not go away with and traffic.
Good luck and enjoy your patio.