Speaking of leggings. These are the leggings and dungaree cap I wore in Korea (1950-51). They're still folded down. Some of us folded them down for comfort, and when the weather permitted, unbloused our trousers. When we went into action as the 1stProvMarBrig, the North Koreans called us 'The Yellow-Legs'. Except for the 'USMC' on our pocket, from a distance they couldn't distinguish us from the Army. We had been ordered to remove our helmet camouflage covers. Surprised the heck out of them.
A little more info about wearing Blues. At Pendleton, back in 1948 or 1949, it was decreed that Marines on liberty north of San Clemente, or it may have been from Clemente northward, had to wear Blues. South of Pendleton, Greens or Khaki were permitted. It certainly got warm in the Summer up around L.A., but it was worth it. The bars were cool anyway.