On Storage > Pools, color icons should appear to the left of the pool status - a 'green' check-circle for HEALTHY, an 'orange' warning triangle for DEGRADED, a 'yellow' lock for LOCKED, a 'blue' circle question mark for UNKNOWN and a 'red' circle X for FAULTED. Colors vary somewhat by theme. BTW we put icons here in a recent ticket, but this one is more specific about choosing the right icon for each state.
When a pool is locked in the new GUI, the symbol changes to a red 'X.
I could see this being a little aggressive to a user. The red 'X' indicates an issue when only locking your pool isn't in issue.
I've spoke with William and the possible status of a pool are: HEALTHY, DEGRADED, UNKNOWN, LOCKED, FAULTED.