Hispano-Moresque (Alhambra style) tiles by Maw & Co. circa 1875.

A large section of the pattern on the right and its matching border (see below) is held by the Gladstone Tile and Pottery Museum, Stoke-on-Trent. Apparently this fine institution also houses a toilet museum. So I'll definitely have to go there then!

https://www.britishmuseum.org/collection/object/H_1980-0307-143

A different palette of five colours...