Question about iodine skin test?

Hello,

I did a skin test using Iodine tincture USP bought at Wallgreens, and the patch still has a faint yellowish color after about 24 hours.

However, when I applied J.CROW's Lugol's 2% solution, the patch quickly disappeared in maybe 6 hours.

I read in many places that the skin test is done using Iodine tincture. I wonder what this implies? Am I Iodine deficient or not? Or maybe I have something that's blocking iodine skin absorption? I have been consciously adding more kelp and seaweed to my diet but I don't think it is related?

After I apply either the tincture or Lugol's, I do feel some activity inside my neck, I wonder if it's a good thing or not.

Does anyone have similar experience or know how to interpret my reactions? I would like to start supplementing iodine if I can confirm that I am deficient. Thank you!