i bought some porcelain tiles from tile mountain. I've already bought bostik opf and evostik TGS grout. Both are grey. But I see tile mountain recommend mapei and say to use white adhesive and light grey grout. Cannot understand this if you don't see the adhesive. Will the stuff I've got be ok for these tiles? http://www.tilemountain.co.uk/calacatta-white-italian-porcelain-2642.html