There's a little more to the story. Essentially all NFL teams always wore their "color" jerseys when playing at home. Tex Schramm determined that by having the Cowboys wear their "whites" for home games instead, that the Cowboy fans would get to see other teams in their "color" uniforms. It was another of those Schramm concepts intended to enhance the fan experience. Only drawback IMO was that we rarely got to see the Cowboys in their "color" uniforms because they were almost always in "whites" on the road as well. This season will be like those "old days".

The navy blue jinx was squashed quite some time ago. If you check those numbers prior to the Jones regime, you'll probably find them lacking more. And it wasn't even so much the win-loss record while wearing the "blues", it was more that they lost big games wearing them. I believe both the Eagles and the Redskins made Dallas wear their "blues" in playoff games (both of which they ending up losing).