[BOAI] word origin of "green" and "gold"

[Shigeki Sugita]

Dear BOAI 2002 vanguards,

Someone please teach me about the original meanings or implications of "green" and "gold" at the time of the first BOAI recommendation. Why was self-archving named as "green" and OA journals as "gold"?

green: green light? "RoMEO-green"?
gold: highest grade? (like "Gold Medal")


Best wishes,
-- 
Shigeki Sugita <ssugita at chiba-u.jp>
Chiba University Library, Japan