Grout colourant long term - Tile Advice

[On one]

Grout colourant.......a long or a short term solution?
I have had a customer I have worked for previously on the phone today asking if I would be interested in a grout removal job on her bathroom walls.
I tried to steer her in the direction of grout colourant(because I didn't want the hassle of grinding the grout out) but she was concerned about this being a long term solution.
Has anyone done grout colouring and been back to see it years later?

 

[Lithofin BOB]

Think longevity of these products will be down to quality of the product ,appplication , but mostly how you maintain them and what with, sure these products will suggest / recomend a specific cleaner to run with these products. General bathroom cleaners will possibly break them down quickly, as with any impregnators, heard good and bad things with these sorts of products , but they may be issues with above

 

[Blunt Tool]

Grout colourant.......a long or a short term solution?
I have had a customer I have worked for previously on the phone today asking if I would be interested in a grout removal job on her bathroom walls.
I tried to steer her in the direction of grout colourant(because I didn't want the hassle of grinding the grout out) but she was concerned about this being a long term solution.
Has anyone done grout colouring and been back to see it years later?

Did a job a good few years back around 10 sq metres on walls. Customer picked grout colour which was Mapei vanilla and silicone to match. I did try and tell her that wasn't sure of colour as bit yellow and suggested Mapei Jasmine grout and silicone but wasn't having none of it! Finished job then week later she phoned to say she had made a mistake and was too yellow. Asked me to regrout and reseal and she would pay me. Wasn't too keen to scape out grout as scared I would chip porcelain tiles so used a grout colourant and resealed, nice and easy and been back a few times now and grout fine

 

[Rookery]

I've used a couple of them, neither very successfully. I would remove the grout with my Fein and re-grout or more likely, turn the job down as it's more trouble than it's worth.