I agree with Glove Man, alot of this area has to do with the Umps interpertation of the rules.
A few years ago I (a Pitcher) used a glove similar to this one, only it was an open back and had a black wrist band on it with the Rawlings logo on it.
A few teams questioned the fact of it being 'two-tonned' The umps said in their mind it was just the lacing and the lacing in the web that was a different colour, so it was allowed.
Rawlings Mill SeriesI know the heart of the hide gloves have a different lacing colour and no one bothers to question. A friend of mine (a Pitcher) actually got his lacing changed to Red and the Umps haven't stopped him from using it.