What visible differences do Geminids have to other meteors
Well done on your observations, I've been completely clouded out.

You are quite right, the Geminids are noted for a variety of colours, and a good number of fireballs, though most observers note a predominiance of yellow meteors This is partly due to their composition and density (coming from a peculiar "rock comet") and partly to their velocity (35km/s) which is fairly fast. 

There is a good chance of seeing some good trails with this shower. Brighter meteors and most fireballs will leave a trail, and the Geminids have more of these than most other showers.