The OD in OD Green stands for Olive Drab. OD Green has been a part of military uniforms (and equipment) since before the Korean War. Learn up.

Cammies, as many of you reading this already know, is a very general term for just about any field uniform. It’s an older term, more readily recognized by those who wore Woodland BDUs than the folks in MultiCam or MARPAT. Happily, it’s still in the military/tactical vernacular. Although it stems from the word camouflage, it is occasionally used to describe single-color uniform patterns like Olive Drab fatigues and the like…although there are just as often referred to as ODs or Khakis, etc.
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The OD in OD Green stands for Olive Drab. OD Green has been a part of military uniforms (and equipment) since before the Korean War. Learn up.
MAS Grey takes its name from the Maritime Assault Suit (MAS Suit, or Maritime Assault Suit System). And it’s actually MAS Gray.
The Woodland camo pattern, also called M81 camo, proved so effective over 2 dozen countries adopted their own variation.
When it comes to military camouflage, the tigerstripe pattern has evolved over the years even though it was never actually an “official” military camo.