Store rooms or bomb shelters in Singapore have very strict regulations governing its renovation and the ventilation outlet pose as an eye sore to many home owners and some spend lots of money hiding it.
I found this simple IKEA LYSBOJ Lamp shade bought for less than $10 (S$3.90) a great solution… when the lamp is switched on it has the added benefit of dehumidifying the cloistered small room.
The original lampshade is stapled together, not using the provided plastic framework and the light bulb is set up from the inside of the bombshelter and the wire has to be extended to reach the powerpoint in the shelter.
Should more details be required, do let me know. Happy redecorating your bomb shelter.