They "were" white.
I bought these for around the house and don't wear white shoes outside.
After just over 1 month.  These are not quite white anymore.  Next to the area under the straps, they look dirty (they're not)

They fit better and are more comfortable than my old inside shoes, also white (and still white after more than a year).

I'm not happy with the dingy look after just 1 month