@pianogrinder, as all shoots are done in front of a blue screen, any blue in girls' costumes would be removed as the clips were made available to play over the display on your computer monitor. This is probably also the reason for shades of pink and purple appearing different in clips to the photos on the cards.
We are told the girls are encouraged to bring their own costumes. Clearly VG Tea has used hers in more than one shoot. Compare her Little Diamond shoot (Card 610) with this from Joymii recently:
http://hosted.joymii.com/fhg/hid076_bie060?affid=2220659