This dress is only seen for a very short time in the breakfast before Mr. Collins proposes to Lizzy. Another one of the "wrap" styles, it has sleeves to the elbows and lovely deocrative pattern around the waist. My theory is that there is a slightly pinker under"dress" since it seems the purple appears to be gathered and sheer.
Probably the best shot. You can sort of see the sheerness. Another thought is that it is a purple fabric, crinkled (if you look closely when you see the shot of the letter from Caroline) that shines pinkish in the light. The ribbon band seems to be embroidered.