You mean the US Army wasn't always Olive Drab?

What about the camouflage color scheme used in Europe before the four color MERDC scheme was adopted?

I'm not even certain what to call the scheme but usually call it "the old 7th Army scheme"; some people call it "the MASSTER scheme." MASSTER was a US Army organization for testing various materials and ideas, and this camouflage scheme was one the MASSTER test programs. I like to call it the 7th Army scheme since it was only used on 7th Army units.

There is a page from the old AFV-G2 magazine which states the 7th Army scheme would be 30277 Sand for the base color, 30117 Earth Red , 34127 Green, and 37038 Black. However, 34127 Green was not one of the colors in the US Army inventory of camouflage paints, but 34151 Light Green was in the inventory and is very similar to 34127, so 34151 Light Green needs to be strongly considered for the 7th Army scheme. The AFV-G2 page states "Reference: VII. Corps Regulation 525-6, dated 1 June 1973." So, one may guess that the 7th Army scheme might have been in use from about 1973 until about 1977 when the four color MERDC scheme began to be used. For people who like numbers, my estimate is that Sand covered 40% of the vehicle, Light Green and Earth Red each covered 25% of the vehicle, and the remaining 10% would be black.

A copy of a different AVF-G2 magazine page shows some black and white pictures of the scheme and a photo caption says, "This scheme and colors were illustrated in AFV-G2 Volume 4, Number 12." That may be the source of the illustration above.

It is interesting that George Bradford's reference file on the MERDC schemes mentions an M113 APC based in the West Germany that used 34151 Light Green and 30117 Earth Red instead of Field Drab and Forest Green as specified for a MERDC scheme typically used in Germany. Interesting because if the 7th Army scheme indeed used Earth Red and Light Green, then a unit would have had relatively large supplies of those colors and may have used those paints when transitioning to the MERDC scheme. Speculation on my part, but interesting.

One other note about the 7th Army scheme is that most of the vehicles have black registration numbers, white bumper codes, the yellow bridge classification circle, and sometimes medium sized black star insignia.

What was happening on the other side of the world?

It seems on the other side of the world the US Army in South Korea briefly used a colorful three color camouflage scheme. Around 1967 and 1968 many vehicles carried an Olive Drab, Earth Yellow, and Black scheme. There are pictures on the Internet of M48A2C's to M30 120mm motars in this scheme. This camouflage consisted of broad bands of Earth Yellow and Black over Olive Drab with each color covering about 1/3 of the vehicle. Apparently there was some pattern used when painting this scheme as vehicles from different units seem to have similar color patterns. White registration numbers and bumper codes were used with the scheme, the yellow bridge classification was always present, but I have not seen star insignia used with the three color scheme.