Does haki color mean anything?

Exactly as the title says.

I have heard multiple times that haki color apparently matters and some are stronger than others.

Is this really the case or is it just a speculation?

Currently I'm at wano act 2 and so far it has not been explained and I'm unsure if it does get explained at all but I have seen many people discussing it.

What sparked my interest in this is how I realized that luffy's haki(specifically conqueror's haki) color seemed to have changed since he first time used it in the marineford arc.

Also to clarify I don't mean color as in haki types color of the supreme king color of arms and color of observation but the actually color of haki specifically first time luffy used conqueror's haki in the marineford arc it was blue and again when he used it in the fishman island arc it was blue again but then later for example when he uses it against katakuri it's red.

Am I reading too much into it does it even matter at all or is it just a design decision?