Currently a planet that is defended by a fleet has a shield icon over the planet icon in the colonies list (on the right hand side of the main view).
If possible i would like to see the same shield over the (currently blank) starbase/shipyard icon in the starbases list when a defending fleet is present.
And maybe even the stats (Beam, Missile, Kinetic, Shield, Point Defense, Armor - like those in the fleet info panel) of the fleet could be squeezed in. This would also be useful in the colonies list.
This to facilitate the planning of where to send additional ships for defense.