Acid on Grout

[Sausage]

I was trying to clean some scale off my tiles last week with a mix of MA and water and i think i might have lightened the color of my grey grout like an idiot. It has a white haze on it now and doesn't look so good. I've read that MA can burn grout as well. Thing is, the grout returns its nice grey color when it is wet, but then the white haze returns when it dries. Is there anything i can put on the grout to keep the wet look, like a sealer or enhancer? Would that restore the grey color? It is still grey, but it looks like someone took a piece of sand paper to i if you know what i mean. It is just above the water line.

Help Please. Don't want do anything to further damage it.

thanks!!!

 

[Lershac]

Sealer would darken it up semi permanently. Re-apply yearly or so