As is true in Hopper's office painting, film costuming was used as a visual shorthand and its elements were applied subtly. Rogers' look as Kitty Foyle was a product of Hollywood's rules of costume, which had evolved by the 1930s into a new fashion realism. Costume codes focused on character coherence, and aimed at a sense of visual "rightness." This meant, of course, that the more spot-on the costume the more the costume as such disappearedã it became simply a matter of a character wearing "normal" clothes.



The collar for example, was a sign, expressively nuanced by size, line, decorative quality, and shape; Kitty's small, neat, crisply starched, simple white collar expressed the ideal character of the working girl. Better yet, it effected metaphorical literalization through design. Life explained, "she wears the white collar which gave her kind its name."
Director Sam Wood confirmed the importance of Life's contribution to the project's authenticity, and wrote:

First we had to find a Kitty Foyle. 'A sassy mick'-- 'a sharecropper in the Dust Bowl of American business' (to quote Morley's words)-- who lives, loves and works just like several million of her White Collar clan. As Life hinted, we tried to show Kitty's life as 'neither too grubby nor too glamorous.' And I hope you will see, as Kitty Foyle says in her own words, 'that there is something courageous about it.' I think you'll agree that Ginger Rogers and Kitty Foyle are the same. Fashion designer Renie's costumes for Ginger might well be within a White Collar Girl's budget. Neat but not too gaudy, as you suggested.