For France and Northwestern Europe maps only, the time in yellow in the upper-right corner is in local timezone.
The colors relates to the difference in time between the lightning strike and map generation time in minutes.
Also an overlay plot of last main synoptic (:00) hour METAR observed thunderstorms and cumulonimbus.
Decoding time stamp example:
Sferics plot/181118/1800
181118/1800: year=18; month=11 (November); day=18; 1800=18:00 UTC
Disclaimer: Lightning data is provided without warranty of any kind as to accuracy or timeliness. Not for protection of life or property, nor valid for insurance quote claims.