Additional indication errors can be caused by a light coating of dust on PAPI lights, tends to blur the white and red to a pink. (bauxite mining sites in particular)
Also if smoke/fire and subsequent air mass movement is anywhere near the approach path (not uncommon during dry season) be prepared for sudden and erratic PAPI indications. I have observed 4 reds then 4 whites instantaneously.
My preference during night ops is to conduct a runway aligned instrument approach with appropriate monitoring of all available resources. V/S, DME/ALT scale ect.
Being current and proficient on night nil slope guidance approaches should be mandatory for all.
