The white jerseys are traditional because theoretically the blue ones are bad luck.
Dallas wore the blue ones on Thanksgiving.
Dallas does have the retro jerseys,
however, because the NFL changed the rule this year allowing only one helmet shell (Not sure how the Bears got away with wearing the retro helmets earlier this year - without the logo), the retro jerseys would not have looked good with the current helmet. This is the hue I wish the dark jerseys were. The colors the NFL has are specific only to the NFL