This article is from the Model Rockets FAQ, by Wolfram von Kiparski with numerous contributions by others.
These are all manufacturers' names for various formulations of 'stuff'
they have added to the propellants to get specific pyrotechnic effects.
Black Jack (Aerotech): low(er) average thrust engine which produces a
dense, dark exhaust to aid in tracking. Also has a distinctive roar.
Note: BJ motors have a slow thrust buildup and long ignition time. Take
care when using this type of motor in a cluster. Also play close
attention to the manufacturer's Maximum Recommended Liftoff Weight
Blue Thunder (Aerotech): high level average thrust engines with a bright
violet-blue flame and very little visible exhaust. Designed for high
thrust, high acceleration lift-offs. Ignites quickly. Very fast thrust
Firestarter (US Rockets): low impulse composite formulation which produces
large numbers of sparks.
Hellfire (Vulcan): a high thrust motor which produces a bright red
Smokey Sam (Vulcan): produces a dark exhaust to aid in tracking.
Silver Streak (Rocketflite/MRED): produces a fine shower of white sparks
during boost (these are actually black powder motors). VERY fast
ignition and thrust buildup.
White Lightning (Aerotech): medium average thrust engine producing a
bright white flame and distinctive roar. Ignites quickly. Moderately
quick thrust buildup.