More to the point what are you using on the shower walls since you are not using the saltillo the shower floor should relate to the shower walls not the bathroom floor

Thanks Patricia! I'd like to use Cle Zellige in weathered white on the walls. If not that, then Wow Mestizage Zellije in white gloss which has terracotta undertones and small areas of terracotta at some edges and in spots. It is much less expensive than the Cle which also has to be shipped from CA. I'm thinking Saltillo cut to 3" x 3" on the shower floor might work with either of those wall tiles.

Cle Zellige Weathered White

Wow Mestizaje

Is ease of cleaning important to you?

I have Saltillo all over my house, so it wouldn't make things much more difficult than they already are.

Thanks for info. Saltillo tiles have several type of finishes or glazes that vary in how often they have to be stripped and resealed. Your choices might be the easy kind. You could prop up a sample tile in your current shower to see how fast soap scum and hard water deposits accumulate and how easy it is to clean. YMWV.