Final answer:
A very thin, transparent application of color to a painting refers to a glaze. It allows light to pass through the color and is often used to create luminosity and depth in a painting.
Step-by-step explanation:
A very thin, transparent application of color to a painting refers to a glaze. A glaze is a thin, transparent layer of paint that is applied over another layer to create a subtle color or texture. It allows light to pass through the color and is often used to create luminosity and depth in a painting. For example, in watercolor painting, artists often use glazes to create soft transitions and build layers of color.