Blue, in general, represents sadness, worry, concern, and regret. The Color Saturation effect very much applies as the West Wing Living Quarters has a light blue wallpaper and a saturated blue carpet, mimicking the bright red/saturated red shown with the couches & elevator blood.
Connected primarily to Wendy, Danny, and Halloran.
See: Red, White, and Blue, Black and Blue
The Credits
In this image · No.5
Ullman’s jacket is a deep blue, reflecting the color of Uncle Sam’s jacket.