Switch,

OK,

The "can-o-worms" simplified version:
Yellow/Dark Blue - good for up to 280 BHP - but with judicious fuel pressure adjustment 308 BHP (ish).

Greens - good for up to 360 BHP

Light Blues - up to 400 BHP some would say 416 BHP

Greys - up to 440 BHP (edited to 440 from my optimistic 480)

OK flame time