They mean here is a heart that is the colour _____. They don't have meaning. I use all the coloured hearts when I'm sending super gay messages to my super gay friends. We send each other rainbow heart messages whenever we're talking about gay shit.
Calendula is a plant. The flower is used to make medicine. Calendula flower is used to prevent muscle spasms, start menstrual periods, and reduce fever. It is also used for treating sore throat and mouth, menstrual cramps, cancer, and stomach and duodenal ulcers. Early research suggests that applying a specific gel (Estromineral Gel, Rottapharm-Madaus) that contains calendula, Lactobacillus sporogenes, isoflavones, and lactic acid to the vagina for 4 weeks reduces symptoms of vaginal atrophy such as vaginal itching, burning, dryness, and pain during intercourse. 2  Leg ulcers.
Calendula, or pot marigold, known as genda phool in Hindi, has been used as a herbal remedy by many cultures for centuries. These flowers are packed with flavanoids that give them their vivid orange colour as well as several health benefits. The petals can be used to brew a tea that you can drink every day.