When tasting a wine, think of “depth of color” as “saturation of color”. Simply put, a wine with a greater depth contains greater concentrations of color and substance, and allows less light to pass through it.
As a result, wines of great depth appear darker, richer in color.
Wines with less depth may appear watery or almost transparent. Depths vary greatly depending on the varietal used to produce the wine, as well as how the wine was fermented and aged.
Depth of color, when used as a measure of quality, typically applies to red wines, as they naturally contain more coloring, tannins, oak, and other components that can alter the wine’s depth.