watercolor
n.a type of paint that you mix with water to use. It is also the name for a picture painted with this style of paint.
n.a pigment used with water as a medium to create paintings; also refers to a work of art produced using this method.
“She is learning how to paint a sunset with watercolor.”
“The artist chose watercolor for the landscape because the transparent colors captured the morning mist perfectly.”
“While oil paints offer rich texture, watercolor allows for a delicate layering of washes that can evoke a sense of light and atmosphere difficult to achieve with heavier media.”
Uncountable when referring to the medium or paint itself; countable when referring to individual paintings.
From water + color.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.