system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does the screen of a calculator turn a blue colour when you press in on it?
gpt
You must be talking about a Liquid Crystal Display (LCD).

If that is the case, then the actual crystals that bend the light are essentially liquid, so if you press down, you deform them, and they half-turn, and begin reflecting random bits of light.