Why do so many old displays/indicators particularly use red lights? Are/Were white diodes harder to create?

Question

Why do so many old displays/indicators particularly use red lights? Are/Were white diodes harder to create?

In: 372

Answer 1

LEDs produce just one color generally, because of the way it produces light – it’s composed of about the same energy photons depending on semiconductor material used and same energy means same color.

So white LEDs are either a triplet of Red+Green+Blue diodes or covered in some phosphorescent coating that produces white light out of single color coming out of diode(maybe not even visible color actually).