Can I make a rainbow in shower? As droplets of shower acts like rain, and say a light bulb will take place of sun. In this scenery, is it possible to make a rainbow?
 A: In principle it is but you need you need to be aware of the problems.
You need one bright source of light of small size like a light bulb with very little of the light being reflected off the walls, ceiling and floor.
This requirement is problematic in that a lot of showers are contained within (white) tiled walls which reflect the light which will make it more difficult to see a rainbow because of this extraneous "background" light.
The light source should preferably not be directly above you, ie in the ceiling, but rather to the side. The reason for not using the spotlight (compact bright source) above a shower is that a (white) base of the shower reflects a great deal of the light which masks any rainbow effect produced.
A potentially dangerous way forward is to have the light source (battery powered and waterproof) at the "back" of the shower remote from the door so light from the background is reduced when looking towards the (open) door and beyond.  
I do not have a picture of a rainbow in a shower but I have one using a hose in the garden.  

Note (look at the shadows) that you need to be between the light source and the water droplets and you will need to move your head and eyes around to get the angles right to observe a rainbow.  
Given the problems I think it unlikely that you will be able to observe a rainbow in a shower without making a special effort to see one but I would be delighted to be proved wrong.
A communal shower area with the walls distant from the water droplets and sunlight coming in through a window might be suitable?
