Colts are banned by name. As follows:
Colt AR-15
Colt Law Enforcement 6920
Colt Match
Colt Sporter
There are three Colt models I know of that are California legal. These would be Colt OLL's there may be more.
Colt Carbine (all have holes in the sides of the receivers, holding a sear block in place that i know of) .250 receiver pins, .155 trigger group pins, marked 5.56
Colt M4 Law Enforcement 6921. .250 receiver pins. 155 trigger group pins, marked 5.56 web sear block
Colt CAR A3 HBAR ELITE 6724 .250 receiver pins (many w/screw not a push pin pivot*) .170 trigger group pins, marked .223. Holes in some receivers for sear block both large and small, and no hole web type sear block receivers.
I could round up photos of most of the differences. I'll need time.
* The pivot pin holes are .250 (that I have seen). There's a hollow threaded pin and screw which requires a screwdriver to remove the upper receiver. This can be changed to a regular push pin takedown pin by drilling a hole in the magazine fence for the takedown pin detent and spring.
edit in: All the Colt 6921 receivers I have seen are marked restricted mil. govt. le use only. It does not change their legal status.