A candle (ner) is the letter Hei ה (=5), five colours shine in it, and they are white, red, green and black, and blue. Vav ו is the light of the candle from inside.
Samael is darkness∞ḥoshekh, the snake is ‘blackening’ (qadrut), and upon him is stated: I shall dress the heavens with blackening, and of his female:... and sackcloth I shall make their covering. (ibid.)
Woe to the soul when it becomes enclothed in their blackness! (Gen. 27:1) And upon it is stated:... and his eyes were dimmed from seeing...