There are 5 different zones.
Here are the parameters which define what color you see on the performance target views, e.g. at what cadence does the cadence box turn from blue to green etc:

Zone 1: Grey
Zone 2: Light Blue
Zone 3: Green
Zone 4: Yellow
Zone 5: Red

Cadence View Zones:
Zone 1: 10 – 60 RPM
Zone 2: 61 – 80 RPM
Zone 3: 81 – 100 RPM
Zone 4: 101 – 120 RPM
Zone 5: > 120 RPM

Power View Zones:
Zone 1: 10 – 60 %FTP
Zone 2: 61 – 80 %FTP
Zone 3: 81 – 100 %FTP
Zone 4: 101 – 120 %FTP
Zone 5: > 120 %FTP

Heart Rate View Zones:
Zone 1: 10 – 60 %MAX HR
Zone 2: 61 – 70 %MAX HR
Zone 3: 71 – 80 %MAX HR
Zone 4: 81 – 90 %MAX HR
Zone 5: 91 – 100 %MAX HR