I've had good luck by buying dry pigments made for staining concrete, and mixing them with water and sugar (as a tackifier) and spraying them on. Pressure wash the pavers first, to get them clean. Then, etch the surface by spraying with a bit of diluted muriatic acid, letting it work for a while, and then pressure wash again. Now, spray on the sugar/pigment mixture. It helps to mist the surface periodically for a few days after you put on the pigment, to help it settle in and penetrate the surface. MIST it, don't get it wet enough to run water off. A misting nozzle like used on stucco and plaster work helps do this right. There are also brush on stains that are more or less paint type products that can be used.
I've had real good success using the pigments, I have done walls like I described, using several different colors of stain sprayed in sequence with my HVLP gun, in patterns to give natural stone appearance (the surface was formed with stone texture skins in place). I have the concrete stained a base color at the plant, and then as soon as the forms are stripped off, and while the concrete is still somewhat green, clean it and stain it with the powders sprayed on like I said.
