Could DCU mean Dress Combat Uniforms?
Could be. I'm not sure.
I know the US Army is BDU for Battle Dress Uniforms,
Correct!
while the US Marines simply called fatigues
Nope ,they call them MARPAT
MARPAT (short for MARine PATtern) is a digital camouflage pattern in use with the United States Marine Corps, introduced with the Marine Corps Combat Utility Uniform (MCCUU), which replaced the Camouflage Utility Uniform. The pattern is formed by a number of small rectangular pixels of color. In theory, it is a far more effective camouflage than standard uniform patterns because it mimics the dappled textures and rough boundaries found in natural settings. This is caused by how the human eye interacts with pixelated images. It is also known as the "digital pattern" or "digi-cammies" because of its micropattern (pixels) rather than the old macropattern (big blobs).
The United States Marine Corps has patented MARPAT, including specifics of its manufacture.[1] By regulation, the pattern and items incorporating it, such as the MCCUU and ILBE backpack, are to be supplied by authorized manufacturers only and are not for general commercial sale, although imitations are available such as "Digital Woodland Camo" or "Digital Desert Camo".
MARPAT is also important in that it identifies warfighters as Marines to their enemies, while its camouflage simultaneously helps Marines to remain concealed. This was demonstrated by a Marine Spokesman who, when MARPAT was launched, said, "We want to be instantly recognised as a force to be reckoned with. We want them to see us coming a mile away in our new uniforms."[