Vallejo Game Colour 72.022 is named Ultramarine Blue. Note that
GW ddn't invent either word ;-]
Vallejo has colour charts up for each of their ranges.
http://www.acrylicosvallejo.com/en_US/game-color/family/18
The Model Air range is aimed more at modelling rather than us tabletop people, that's why it has different camo/military colours rather than the much more colourful bits we use for
SF/Fantasy. The Game Colour range is meant for tabletop however, comes in the same type of bottles with the same price, but is a bit thicker.
I've had no problems at all when airbrushing Vallejo Game Colour thinned with Vallejo Airbrush Thinner. Since I also like to check the Model Air paint in a secondary container and thin it as I see fit, the only pratical difference is the amount of thinner I add. Note that the Game Colour paint is supposed to dry faster (but it wont until you sprayed it) and leave a more resilient coat of paint, since they expect the models to be handled.