RJ had established a colour code for the flows, IRRC. I think it's basically pure light with a tinge. It's not really a difficult (nor expensive) effect to design or produce once the recipe has been established.

The way I'd do it, that I think would respect the books, is to use a POV camera (showing the action through the eyes of a specific character) from time to time. In a scene between Aes Sedai, you show the effects on all shots. If it's a scene between a channeler and non-channeler, you either don't show the flows at all, or you have a few "POV shot" from the channeler's perspective, showing his weaving.

This would need prior exposition, of course. In the first episode, Moiraine's flows would never been seen, just the effects of her channeling. We would begin to see the flows, and she would explain to the audience only other female channelers see them, in the scene wheN she teaches Egwene to embrace the source. We'd have shot from Egwene's POV where she would see Moiraine's flows, and her weaving of them. We would have reaction shots from Rand where he sees only the result, the ball of light.

Before long those simple conventions would be firmly established in the audience's mind. It's not so different from the books, where the weaving is described in the POV of channelers, and only the visible effects in the POV of non-channelers.

The Cleansing would obviously show both saidin and saidar in all shots (even though only Rand/Nynaeve see them), except perhaps reminding the audience characters like Min or Lan don't see anything by showing things from their perspective for a few shots.

The rest are simple rules to establish... if you have a Graendal shot and she gets attacked by saidin, you show only the effects. If it's Demandred who does, you can show the saidin flows. Much as in the books, the audience would gradually get used to those conventions.

That would work the same whether the adaptation is animated or live action.