I keep seeing posts talking about Colt Green Label or Blue Label rifles. What does that mean and how many different colors are there.

Generally speaking about Colt  AR's:

Green Label: made in 1989 or earlier.  The lower didn't have a sear block.  Was a slab side lower (no raised rib around the mag release).  Upper had a bayo lug.

Blue Label:  Sear block in lower.  Raised "fence" around the mag release.  No bayo lug.

White Label:  Not as common.  White label guns mixed the two above scenarios (example: Blue label lower and Green label upper)

The "label" refers to the label on the box that the gun came in.  Different colors were used when changes were made.

Others, please add or correct any info.

scottMO  

You can never be sure with Colt. I have a Blue label w/o the sear block. Thats whats so nice about Colts nothing is cut an dried!

OK, now I know what the colors mean, also that in some cases it doesn't mean anything for sure.

Take a gander here;

www.biggerhammer.net/ar15/coltcolors.html

Thanks JohnM. That was a lot of info.