The meaning behind a neighbor always having a blue light or any other color on could vary depending on the context and the specific circumstances. Here are a few possibilities:
Decorative or aesthetic choice: Some people choose to use colored lights for decorative purposes, especially during holidays or special occasions. It could be a personal preference of your neighbor to use a blue light or other colors to enhance the ambiance of their home or garden.
Security or safety indication: Certain colored lights, such as blue or green, are sometimes used to indicate security systems or emergency measures. For example, some neighborhoods or communities use blue lights to indicate the presence of neighborhood watch programs or security cameras. Green lights may indicate the presence of a medical facility or a safe location during emergencies. It's possible that your neighbor is using such lights for these purposes.
Personal preference or significance: Some individuals may have personal reasons for using specific colored lights. For instance, someone might use a blue light to support a cause or raise awareness, such as autism awareness. Alternatively, they may simply enjoy the color blue and choose to incorporate it into their lighting choices.
Technical or electrical reasons: In some cases, the consistent presence of a specific color light could be due to a technical or electrical issue. For example, there might be a malfunctioning light fixture that only emits a particular color. It could be worth considering this possibility if the light remains unchanged for an extended period.
To determine the specific meaning behind your neighbor's choice of a blue light or any other color, it would be best to inquire directly with them. They can provide insight into their intentions and clarify the significance behind their choice.