There are a couple products I would probably try:

Jomax is an old line cleaner which is mixed with bleach to make a very effective cleaning solution. A quart is mixed with four gallons of water and 3 quarts of household bleach to produce 5 gallons of solution. Jomax contains a chemical which further activates the bleach, a detergent and additional mildecides. I use this product on my concrete exposed aggragate patio every year to get rid of the algae and mildew from the long , damp Portland winters. Its application followed by a vigorous rinse with the power washer is very effective.

Another product which is a great concrete cleaner is Behr's All In One Deck Cleaner. This is basically oxalic acid with the addition of some enzymes for cleaning. I discover by accident how good a concrete cleaner it is. I was using this product to bleach out my cedar fences. While mixing it on my driveway, I was splashing some of the solution on the driveway. Low and behold, that area of the driveway looked like new! After that, I treated the whole driveway.

It also did a good job of getting the rust stains out of the sidewalk where I stupidly had left some of the 5% iron containing grass fertilizer had made stains.

I see no reason why these faded pavers good not be stained with a transparent concrete stain after cleaning to reinstate some of the color.