Hey @kaetliR , when I look at the walk graph on my phone app the colors are an indication of your heart rate, blue for below exercise zone, yellow is fat burn zone, orange cardio, and red is your peak heart rate. If I'm looking at my computer the colors I have are- yellow, light exercise, orange-moderate, and green for intense. I believe the Fitbit device keeps track of your heart rate and then can tell which zone you're in. Fitbit has a logarithm for this but you can get an estimate of your peak heart rate by subtracting your age from 220. Keep on stepping.
