IPA: //ˈpeɪl.i//
KK: /ˈpeɪl li/
In a way that is light in color or lacking in brightness; not strong or vivid.
The sky was palely lit by the early morning sun.
Palely → It is formed from "pale" (from Old French *pale*, meaning lacking color or brightness) and "-ly" (meaning in a manner). The word "palely" means in a manner that is lacking color or brightness.
Think of the word 'pale' which means lacking color, and remember that 'palely' describes something done in a pale manner.