Ketone bodies are produced by the liver during gluconeogenesis when glucose levels are low. Urine ketone testing is performed to monitor for ketosis, which can occur in people with diabetes when blood sugar levels are too high or when they are ill. The dipstick test uses nitroprusside to produce a color change ranging from light pink for negative results to darker pink/purple for positive ketone levels. Results are compared to color blocks on the container to interpret ketone concentration in the urine.