] 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.
I understand the point, but must observe that the Bennets aren't that wealthy. Certainly they would wear their best white outfits for major occasions, but not for "everyday" as they seem to in PP2.
I'm still amazed to see that they had Elizabeth traveling in a white dress (all the dust, don't you know?), though she was wearing a full lenghth cloak, presumably to help keep it clean.