Different colour needles are common, especially amongst the non genuine items. One is shorter(10.5mm, I think) and one is longer(11mm). The one to use is the one that works best with your float setup, it doesn't close it to early and on the other end of the spectrum doesnt stay open after the float chamber is full. I generally prefer the longer ones and file some off the top if i need to.
Long kill rubbers were used in the g4's and LM's up until the end of the full crank engine. With the intro of the powertorque the short kill rubber was introduced with the longer and stepped pin. A far more superior setup than the long rubber which had a tendency to tear off at the end as the cam in the carby came around and tripped it.
