Bought some 'grey' grout. It looked light grey in power form, we
thought it might be too light so took it back and exchanged it for
charcoal which looked as it sounds, really dark grey in powder form.

I've now done the grouting with charcoal, looked fine as it went in
but now it's dry it looks like light grey. Is this the norm? In order
to get a dark grey grey should I have bought black grout??