SiFu welcolme back.
Recently i heard my friend telling me.
He went to temple and accidentally got his eye open becoming YIn Yang Yen.
then he seek for sifu to close back the Yin yang Yen.
The bestt the sifu did is close partially only. he still can see spirits but not full form and cant see body but just spirits.

So, i heard he said spirit that has different colour
Yellow light: Human
Green light: Natural Spirit ( Neutral, Forest spirit, Earthy spirit and etc)
Red Light: Aggressive spirit. I heard my friend said when red spirit approach near you, better avoid it as fast as you can.

Ya i think is white light