Patchy Colour hardener

[hartz]

Hi

 

I have some concrete slabs the intention was to polish them. I put a white colour hardener down which was taken off in patches with the grinder. Any suggestions around hiding this with a stain or something would be appreciated. I don't think grinding the whole thing down another 5mm is possible for me.

 

Thanks

[hartz]

I was thinking of acid staining with 3 shades of brown and trying to camouflage it with a mottled pattern?