'Open' signs on commercial buildings - why are most of them red? [closed]

1. Why are open signs red?
2. Which Colour is best for signboard?

Why are open signs red?

The primary reason behind the phenomena is that the color red enhances physical reactions — it's programmed into our psyche as a cue for danger. Retailers use this information to grab a customer's attention with red signs and cue them to take action by making a purchase.

Which Colour is best for signboard?

The means that the best colours for pavement signs and outdoor signage in general are bright and bold. Fire engine red, neon green, bright yellow, and electric blue are all popular and effective choices. However, don't write off black, white, tan, and grey so quickly.