Green Lanyards - when there in May (twice in two weeks, don't ask), I saw one green lanyard for every three gold lanyards...so that's pretty good! And seriously, the GOOD STUFF is on the green lanyards! One I know is the lady that is hostess for The Plaza restaurant. (It's behind the ice cream store)
As to how many pins to bring for trading...that depends on how much they like to do it....my youngest son is now 16 and he and I REALLY love the pin trading at the parks. I look at every lanyard, but pass on most because I look for specific pins...or for something to catch my eye. On my last trip down...without my son....I traded about 20 times...in three days. But it was just a trading/walking trip for me, since my DH was there on business and I didn't have the kids. Rode very few rides, did very little else.
If you are doing other things (assuming), I'd say 3-5 traders a day per person is more than reasonable. Besides, you can always trade away what you get, and trade up even if you see something else you like better.
And IF you find yourself in a bind, without enough traders because you went crazy and traded a lot, you can always buy a box of pins from one of the pin stores...I found the box with the cutie heads (maybe 6-7 pins in there for $22.50) was a good deal in a bind....
Enjoy! It's a blast!
Patty