|Scottish country dancers--look how cute they are! yay red shoes!|
Colored evening slippers for ladies were quite fashionable during the early 19th century, although white was still standard.
|3 examples from the Victoria and Albert Museum, c. 1790s|
|from the Met Museum, c.1820|
...but given that I've also seen a couple of extant pairs of tartan slippers from the mid-19th century, let's hope I don't find a modern source for those anytime soon.