Why do some IBM PS/2's have a red switch, while others have a white switch?
Does the red or white power switch on the power supply signify something about the model number, CPU, or options that the computer shipped with?
I don't think the color of the power switch signifies anything except the age of that model. Originally the power switches were red, and at some point they changed to white.
Similarly, at some point the floppy drive eject button changed from large to small. It's just another minor styling change that was applied as time passed by.