There was a period during the Cold War (50's and 60's) when fighter aircraft in particular had bare metal finishes and also very high visibility markings as well. Perhaps it had to do with the high speed of the jet age, but many other types of aircraft had similar paint schemes as well - including slow transport types.
Another very common paint scheme at the time, was strategic bombers (and even some fighters) painted in anti-flash white, for protection against the blinding flash associated with nuclear explosions. That tradition continues with the Tu-160 White Swan to this day.
I think it all changed with the advent of the Vietnam War - combat aircraft reverted back to camouflage paint jobs. Low level penetration for bombers also brought back cammo for these types. The US Navy was an exception with most still painted in high viz colours and markings. Eventually it all changed to low viz markings and paint jobs.
Another very common paint scheme at the time, was strategic bombers (and even some fighters) painted in anti-flash white, for protection against the blinding flash associated with nuclear explosions. That tradition continues with the Tu-160 White Swan to this day.
I think it all changed with the advent of the Vietnam War - combat aircraft reverted back to camouflage paint jobs. Low level penetration for bombers also brought back cammo for these types. The US Navy was an exception with most still painted in high viz colours and markings. Eventually it all changed to low viz markings and paint jobs.