thank you for the reply. this room is very beautiful!!!!!

I googled silver travertine but it shows up as a grey travertine slab. Not as the beige shown in this picture. Where could I find this color of Travertine slab? Does the slab need polishing?

Since travertine is a natural stone, it is going to vary somewhat in color. You need to contact a local stone yard or a company that would fabricate granite countertops, etc. to see in person what they have, as you would purchase the stone from some place like that anyways.

Thank you !

I would like to do a similar treatment on my fireplace wall which is 11' x 20' and spoke to my granite and stone installer and they told me that the travertine slabs were too heavy to install on a vertical wall.
How was this on done? Also, I do not see any seams.

Not true too heavy for wall installation. I have a floor to ceiling wall of silver travertine behind my master bath tub. AND a entire fireplace wall in my Master Bedroom. Can be done. You just need the right people.