Stage 6 clutch spring colour HELP

i have a stage 6 sport clutch not the black one tho! i am running a,
50cc malossi sport cylinder,
polini speed control
yasuni city r
malossi mhr reed + block
polini 17.5 carb
malossi open filter
4.9 rollers

at the moment i am using yellow clutch springs which came with an old leovince exhaust but the bike doesnt pull away good and bogs for a few seconds then takes off! i've tried everything such as jet, carb tuning and roller weights but have come 2 the conclusion it must be springs!

what colour stage 6 springs should i order? seeing as i have a sport cylinder kit!

thanks cole!