Does anyone know what the Orange ORM Map does?  
I know it is a channel packed map, but I don't know what function it serves. 

The format does expect the textures in a specific format, however. The Base Color, Normal, and Emission textures are saved as individual files, preferably a PNG as the format is lossless. The Ambient Occlusion, Roughness, and Metallictextures are saved in a single channel-packed texture to reduce the number of texture loads. The textures need to be packed into the channels of your texture as follows:

• Red: Ambient Occlusion
• Green: Roughness
• Blue: Metallic

Going forward, I will refer to this channel-packed texture as the ORM texture for Occlusion, Roughness, and Metallic.




So Orange is what you see when all 3 Layers are overlayed ...   here Red over Green   :-)

i thought the standards should have been MRAO. LOL.