Kirk Alyn in a publicity shot for the 1948 movie serial “Superman”, in the man of steel’s first screen appearance.
The photo above shows the costume in the colours the viewer is supposed to imagine seeing but, in reality, were more like the picture below. It was common, in the days of black and white, to use colours that would appear to be something else, so grey would stand in for blue, white for yellow, and brown for red. If the costume had actually been the correct colours, it would probably have looked wrong on the screen.
You can read more about the black and white version of the costume in this post about George Reeves on Jim’s World and Welcome To It