And this seemed to him perfectly clear.

When the princess came to them, they were sitting side by side on the chest, sorting the dresses and disputing over Kitty's wanting to give Dunyasha the brown dress she had been wearing when Levin proposed to her, while he insisted that that dress must never be given away, but Dunyasha must have the blue one.

"How is it you don't see? She's a brunette, and it won't suit her....

I've worked it all out.