Just browsing the web and ive found that trakpower are introducing a new series of lipo's that are not gold but black - hence the name 'Dark Series'
These are them:
TPDS50002S - TRAKPOWER DARK SERIES 40C 5000MAH STICK PACK 
TPDS46502SSP - TRAKPOWER DARK SERIES 35C 4650MAH - could be a saddle pack ?
TPDS36002S - TRAKPOWER DARK SERIES 35C 3600MAH STICK PACK
Cheers