Why is the Shinto symbol always red?

The Shinto symbol, often seen in the form of torii gates, is typically painted red to symbolize purification and protection against evil spirits. Red is considered a powerful color in Japanese culture, embodying vitality and life, which aligns with Shinto's reverence for nature and the kami (spirits). Additionally, the bright hue serves to visually stand out against the natural surroundings, marking sacred spaces.