Yes, PALENESSES is a Scrabble word!

Letter values in Scrabble US: P 3, A 1, L 1, E 1, N 1, E 1, S 1, S 1, E 1, S 1.

Is it a valid word?

PALENESSES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

unnatural lack of color in the skin (as from bruising or sickness or emotional distress)
the property of having a naturally light complexion
being deficient in color

Not playable in Scrabble US: ACHROMASIA, PALLIDITY.