I personally drink green because I prefer the taste, but just for fun, I checked the Nutrition Facts, and carbohydrates are the same on red and green (12g), all sugar.
Nutritional "facts" are total fraud.
Case in point, look at the dietary fiber content and % of recommended daily values on these two packages (also why are serving sizes different on these very similar products?):
What you see on the milk packages might be a result of rounding. I've seen packages that clearly had more sugars on the blue vs red.
I'm sure DDF health & nutrition resident expert
@chevron will back me up on this. It's a simple rule of physics, if some of the volume is occupied by fat, there will be less volume of other content (including sugars). It is also know that fats slow the absorption of carbs. That's a good thing.