what years did the US Marines wear red nylon running shorts?

I'm not aware of it. We ran in utility uniforms up until they started using running shorts and running shoes for the people who couldn't hack utes and boots.

**Schlum, I went to boot camp in the 1960's and we didn't have PT shorts or running shoes, we exercised and ran in boots and utes. We ran the PFT in boots. I served into the 70's and never saw running shoes or PT shorts. I NEVER had PT shorts or tennis shoes.

The Marine jacket and trousers are blue on the dress blue uniform. But, the two colors you would see for shorts and T shirts are red and gold. I agree, you don't see blue as a color used in the Marine Corps other than dress blues. Marine colors are red and gold.

They may have had red PT shorts after I left in the 70's and before 1990. That would help narrow it down.

**EDIT-- I looked at some photos and they did have green running shorts and t-shirts in the early 60's. They were wearing combat boots for PT. Maybe because of the Vietnam buildup we never got the running shorts.

the only plain colored t-shirts that Marines are not allowed to wear while on leave or liberty are plain white t-shirts. the reason for this is that plain white t-shirts are part of the dress and service uniforms I don't know the exact order number but it is under the uniform regulations Sgt. USMC

Never saw them in red. The Marine primary color is blue.

They never did.