Response surface methodology was used to evaluate the effect of temperature, time and solid–liquid ratio on the extraction of compounds from black rice. A temperature of 34.7 °C, 80 min extraction and a solid–liquid ratio of 1:30 proved to be the best condition to maximize the total contents of flavonoids, anthocyanins, phenolics and in vitro antioxidant activity of a black rice extract. The use of citric acid–ethanol is noteworthy because it is a non-toxic solvent system that could be used to extract bioactive and pigmented compounds from black rice, and the extracts could be used by the food industry as a natural colorant.