] ] Even in this modern age of automatic washing machines and synthetic fabrics, white can still be an extremely impractical color. I can't help but think how much more impractical it must have been in Regency times, even for people who had houses full of servants.
] Wearing white was done often precisely because it was so impractical to wash and care for. It signified that servants were on hand to clean to the owner's content. Status-ey.
(Hi, I'm new-- signed in yesterday, I think, but have lurked off & on for some time.)
Servants were relatively cheap during the Regency period, if I remember correctly-- even the Bates ladies in Emma had one full-time worker. Light muslins were popular for a variety of reasons, as well... mostly because they were lightweight, draped well, could be reworked easily, and washed well (or at least better than silks). Stiffer, heavier fabrics are more difficult to care for, and are less versatile.
It also seems like there were a couple of prevailing "looks" that were popular at the time-- the neoclassic style that would have called for lighter, more flowing clothes, and the exotic, Eastern look with its elaborate trims & deep colors.
I'm not a historian by any stretch, but that's what I've more or less inferred from what's been written on the period.