Identifying the type of mint. Just to confuse the picture even more, there is a chocolate mint which has purplish stolons. There are, in fact, hundreds of varieties of mint, some of which are commercially grown for oil extraction or for leaf drying, and a lot of which haven't even been given names, being known as Mint 341, etc.
Simply put, watercolor is a painting compound using water-soluble pigments that are either transparent or opaque. Because of the medium itself as well as the paper to which it is applied, watercolor is frequently thought of as a fugitive medium.
A Country House and Park, Thomas Malton II (1748-1804), 1779, watercolour. Watercolour paint is made by mixing pigments with a binder, usually gum arabic, and then applying it with water to a support such as vellum (fine animal skin) or paper. The water evaporates and the binder fixes the pigment to the support.