Are they color codes or they are unintentional?
They are made of millions of transistors but normal transistors are normally black or silver.
As Richard Feynman said "light can be viewed as either a particle in some cases or a wave, but if you treat it as a wave then you are always right" I am quoting him from one of his lectures from memory so the exact wording may not be correct but the sentiment is.Light can behave like a wave or particle depending on the type of medium light travels through.