Colour Restore?

[Aspesim]

HI Guys

I wonder if you can advise...

I've laid some Topps Q Rock tiles (black) and I've used grout remover and cement-away to clean up after myself however, when I compare a non laid tile to the ones which I've laid there is a noticeable colour change, The black has gone slate gray.

Is there a product I can use to bring back the jet black colour too the tiles?

As always thanks for you help

Regards
Aspesim

[jay]

pics might help