What does green light and blue light mean?

Green light typically signifies permission or safety, often used in traffic signals to indicate that vehicles can proceed. In a broader context, it can represent positive approval or go-ahead in various situations. Blue light, on the other hand, is often associated with alerts and warnings, particularly in emergency services or technology contexts. In some cases, blue light exposure can also refer to the light emitted from screens, which has implications for eye health and sleep patterns.