Earlier printings of Against The Giants (AD&D Module G1-2-3) had a green cover; later printings were a green so dark as to be almost black.
Dungeons & Dragons, Gaming History
Against The Giants printings

Dungeons & Dragons, Gaming History
Earlier printings of Against The Giants (AD&D Module G1-2-3) had a green cover; later printings were a green so dark as to be almost black.