The color zones/bars help you interpret whether your HRV is relatively lower or higher. You have access to real time feedback, as well as historical data through your HRV bar chart. Red=tense, yellow=alert, gray=neutral, green=calm, blue=restore. Your Lief categorizes your unique HRV range into quintiles, where the 0-20th percentile=red, 20th-40th percentile=yellow, 40th-60th percentile=gray, 60th-80th percentile=green, and 80th-100th percentile=blue. The goal is to stay in the gray, green, and blue zones as much as possible, which Lief's autodosing helps you do.