Fitbit’s newest fitness tracker, the Charge 5, might be the biggest change to the Charge line yet. It has a color screen, the first for a Charge, and you can opt to keep the screen on all the time. It has a new rounded design that’s thinner than the Charge 4. New sensors measure how your body responds to stress. But all that change also comes at a higher $179.95 price, a $30 increase from the Charge 4.