Here is a small app to help blink lights either from an automation in HA or from Appdaemon directly.
You call the app by firing an event named blink_light.
You can pass a single light entity or a light group as data. If the entity is a light group, each individual light is restored to its previous state. You can also pass color, brightness, duration etc. when you fire the event.
In addition to blinking, you can also make the light loop between a list of colors.
Might be useful when the light entity does not have the blink or color loop capabilities.