A question of concrete & colour.......

I have a friend who had a patio poured and dyed green. Supposedly the job was done properly, and the concrete was dyed all the way through. No dice.
She failed to apply sealer to it last year, and now apparently the dye has faded out of the surface. Several people she has contacted have said it cannot be re-dyed.

I happen to think if there is anyway this can be accomplished, some of you among the teeming millions will know a way.

Btw, I already sugested a coloured epoxy coating, readily available to do it yourselfers, but she doesn’t want the uniform opaque colour. She has a terrazzo effect, and wants to keep it.

Any suggestions?

The way that most coloured concrete is made is by applying a powdered dye to the concrete right after it has been poured. If it is dry, it can’t be dyed. It may still be able to be stained, but that would probably need to be re-applied every year or two.

This thread got opened twice somehow (is it just me, or did the whole internet seem slow today?), so I’ll lock this one and direct readers to its twin, located here.