Velvet - How Do You Know When to Stop Medicating?

I have been treating 2 male bettas (separate containers) for Velvet. Not positive that's what they had but did a lot of research on line and that was the best diagnosis I could come up with. I didn't really see them trying to scratch but the one who appeared to have the worst case was body surfing where the water pours in from the filter (Eclipse) and as I understand it bettas don't normally like moving water so I thought maybe he was doing this because he itched. t\They were both still eating and swimming. In any case, both had gold dusting on fins and the one that had it worse even had some rust color to his fins (normally he is a midnight blue).

So, I treated them this week with a with Maracide and Maracyn 2 and raised their wate temp. Tried to blackout their containers but as they are only in 1/2 gal. right now (waiting for tanks to cycle), the water seemed to get too hot when I covered them up so I had to take the black cloth I had on them off. Noticed little white things floating on top of the water as soon as I medicated them. Too small to see what they were but I assumed the were parasites coming off. Completed both treatments and they both seem to feel fine, eating, swimming, more active than before treatment. But the gold/rust color is still there. Does that mean the Velvet is still there or does it just take awhile for the color to go away?

Should I start another round of treatment and continue until all the gold/rust is gone or just keep doing water changes and the color will improve with time?

Thanks,
MaryAlice