Lightning sparkles don't seem like necessarily related to CoC since they appeared in other occasions as well for example.
I think the best argument that can be advanced here is in regards to them being likely strictly related to haki attacks in general. But not always portrayed either of course.
About colors of basic CoA, Oda displayed the lightning sparkles in the Luffy v Katakuri occasion for the first time ever IIRC so it that was really the first time ever it might be that when the sparkles are displayed alongside basic CoA an advanced color is always into play, but I'm not that completely sold either. It looks feasible and probably the case however.