I'm sure that as the war went along there was also a lot of "field acquisitions", especially among the Confederate Army, since it was notoriously hard to supply. While there was surely some resistance to wearing "Yankee Blue", I'm sure that a confederate soldier, having ruined his jacket in the winter, would be happy to have a jacket "acquired" from a union soldier.:rolleyes:

And as Todd has said, there was a wide variety of uniforms anyway, especially at the beginning.

I remember a movie I saw once (I have no idea the title or even the actors) where a confederate soldier had come from a northern state and had no uniform to wear except his old one, which happened to be blue. He was subjected to a lot of prejudice because of this, but still fought alongside the confederate troops.