I'm pretty sure it's a bad sign when your aura is this color.
Black Aura price in Growtopia: sells for about 20 DL, buyers pay about 8 DL (median of 68 offers from community Discords, past 30 days). Live price chart and the latest buy and sell offers.
Recently sold at: AYABAI, FETPES, GECSMAIN, FFARMING, ZLECI