Discoloured flags - Discoloured flags

[kopite31]

I recently used the advice on this site, on how to remove rust stains from paving slabs, by using lemon juice.
It did work in removing the stains, however it has also left the half of the slab I put the lemon juice on, discoloured. It is a lighter, but tired looking, shade of white, compared to the original white shade it was.
The slabs are fairly new (only had the driveway laid in the last few weeks). Does anybody have any advice on how I could possibly get the slab back to it's original shade (or at least closer to resembling it)?
Many thanks in advance.
Lee

[RAPressureWashing]

Lee,
Any chance you could post a photo?
How long did you leave the lemon juice on for, and I take it you did rinse it off really well?
What are the slabs, stone or conrete etc.