Is gray grout supposed to turn white when wet?

Gray grout should always be gray grout may be darker if wet, there are some grout products to use to seal the grout to prevent water penetration that could help, if grouts cracking and a tile has popped there is movement in the floor, the tiler should have used flexible adhesive and grout and some sort of floor board/matting product on the floor. silicon is a skill! I'm a professional tiler and I struggle to do silicon I have done a job of a lady that really wanted me to do the silicon and It didn't look how I had planned, I'm so fussy on having it look good I had to go back 3 times to re do silicon at my own expense as its all about a happy customer and a professional finish. I think if your paying for professional materials and labour you should get a professional finish, I would say my fussy mate the tiler came over and had a look and said the silicon needs re doing and recommended grout protection spray or another product to keep the gray colour or re grout the floor to look how you wanted, I hear about trades men getting away with lots of things here and there but these days people are getting smart with buying snag list books on line that give you all the information you need to know I have had some seriously fussy customers over the years and I have learnt a

Get him/ her back to put it right.. If they don't respond .. Threaten with small claims.. Good luck GW.