Among the various colored hearts, blue represents deep trust, harmony, and loyalty. It's considered a platonic and less emotionally intense heart, perfect for showing support without romantic implications.

Interestingly, the blue heart is often used on social media by brands to express trust with their customers. It's also used to support sports teams with blue uniforms or to back social campaigns like autism awareness. It's a versatile heart that expresses everything from friendship and corporate loyalty to social support.