Reveal what's in your heart with the Colour-changing Hidden Message Heart Charm. At room temperature, this charm looks like a rounded heart with bright red enamel. But when you hold the charm, it heats up and the enamel turns pink, revealing a secret message: ''I <3 U” on one side of the heart and “ALWAYS” on the other. A playful charm for the one you love with an extra element of surprise.