Black Grout

I finally decided on the tile and grout for my backsplash. After many hours in the store floor. Well coulis black and tan / brown and travertine WHITE! I do not think anything of it until I read something on tile grout die!
Is there something I can do to seal the travertine or something so I can dye gray color or a little weird when I'm injecting?
Thank you for any help!

For a travertine backsplash grouting I recommend black. It will really accentuate any imperfections in the tiles, and you laying of them (your groutlines must be absolutely perfect and consistany size)

If you're really dead located on the color, the travertine with a sealer attached impregnation. I 511. Blue Bottle, Home Depot carries it. 1 small bottle will seal your backsplash repeatedly. Nice to 2 layers as directed, then grout, then seal again after grout has cured (three days after grouting) so as not to spoil the groutlines with dirt / oil and make a mess every time you clean the backsplash below. Good luck!

In the unsealed tiles they make a grout bag avaialable in any hardware store that is similar to a cake piping bag .. even a cake piping bag works .. You must individually grout lines one by one instead of scribbling on the whole tile. . heres a link and image
http://plasticgroutbags.com/