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 cream can help soother inflamed skin. There is some evidence that tea tree oil or lavender applied to the skin may reduce allergic skin reactions caused by histamine-induced inflammation. Lavender oil may also be helpful.