Dont' know if this post is too late. I work a lot with Mapei and love the stuff. One thing I've noticed is that as you mix it, you get 'flames' of colour coming through in the mix, i.e. with Jasmine you'll see flashes of yellow in the mix as you stir it around. Very important , me thinks, is to make sure that you've mixed it properly to get an even colour. I often just mix with a spatula in a bucket and don't measure out my water according to what the bag says (and not trying to promote this either) as I just get a feel for the mix. So, whatever you mix with, just make sure you've done it thoroughly. I've never had Mapei disappoint me on colour consistency. I've used some others, especially in grey, that have messed me around when I started off ... but I think it was due to using too wet a sponge when wiping down. I think with opaque they mean hazyness on the tile. However with Mapei you've got to watch your grout by testing as recommended previously. Otherwise you'll work up quite a sweat trying to clean it off ... not fun.