Heart rate zone colour

In the power, cadence and heart rate data box at the top left…

The heart symbol and ‘BPM’ text could change colour to show what heart rate zone you are in. At the minute, I look at my watch for this info (bit tricky when on the aero bars and rollers!), so having it right there on the screen would be really helpful.

Should be quite an easy enhancement to make?

Thanks!