How to rainbow effect for natural lighting?

Looking for a way to be able to get rainbow effect from natural lighting coming in through a window, without actually installing some sort of rainbow type cling film or something permanently to the window. Both in my own home, and when shooting others, I'd like to be able to have something temp to go up to cast some diffracted light onto a model or the scene.

Trying to brainstorm some sort of way to clip/temporarily place some sort of appropriate film over a window to get the desired effect without having to go throught the standard install process of putting cling film on a window.

Anyone done this or have ideas on a way to do this that could be easily removed/carried to different shooting locations?