The term "colouristic" (or "coloristic") is an adjective that relates to the use or choice of colors, especially by an artist. It describes something that is of or relating to color or coloring, often emphasizing a special or skillful use of color. For example, "colouristic effects" refer to effects created through the use of color.

In summary, "colouristic" pertains to the artistic or skillful application of color in visual works.