Hi,
Just been replacing a shower unit and tried to use all the best products. Swapped rotten plasterboard with AquaPanel, BAL tanked, BAL White Star adhesive, then grouted with Microflex. However impressed I was with the finished job with my bright white tiles, once the grout dried I realised the online company I bought the grout from has sent me Ivory grout instead of White. So I now have a very neat job in an ultra waterproof shower but with the wrong colour grout. Here's my options to fix the 24 hour old microflex grout (change the ivory grout to white):
1) Fully scrape out the grout and regrout with white microflex
2) Scrape out the grout to a depth of 2mm?? and regrout with white microflex
3) Use a grout remover product (Microrevive??) and regrout with white microflex
4) Paint the grout with a white grout reviver pen (e.g. Unibond)
I've tried 4) so far and it works well for now, but I can't imagine it will last the test of time.
Appreciate your advice to give the best balance of quality of finish versus effort.
Many thanks
P.S. I will be phoning the online company to give them an ear-bashing.

Surely it said Ivory on the bag ??

Yeah, it did in the bottom right corner, which I didn't feel the need to check. I had read the shipping note however in the packaging however which did say white on it, so they must have picked the wrong item in the warehouse. I shall be checking things obsessively in the future, but in this case presumed I was using what I had ordered.

I would feel the only course of action would be to remove the grout, which is a painstacking job and then regrout with the correct colour.
Aquamix make a grout colourant which I have used succesfully on patchy grey flor grout. How well white would work over Ivory I cant say.

Remove more than 2mm so you dont have to revisit at a later date.

So I've embraced your expert advice, got the elbow grease out and started removing the grout. Turns out it was fairly easy to remove with a hand tool (1 hour per square metre), probably due to it not being fully hardened yet, and is now ready for the new white grout. For anyone else that falls into this trap I'd definitely recommend removing the grout ASAP after laying before it fully hardens. I would also recommend triple checking products before use, especially when ordering from REMOVED as this is the second time they have sent the wrong item in three orders. They may be cheap but this may be due to them paying warehouse staff peanuts and getting monkeys....

Thanks guys for your advice on this topic and on others throughout the site, from which I have learned a huge amount on tiling professionally.