Color tone reference

Quick answer：

Color tone reference typically refers to the specific color values used in various contexts such as graphic design, photography, and art. In graphic design, color tone refers to the specific shade of a color, which can be adjusted to achieve desired visual effects. In photography, it relates to the hue and saturation of colors captured in an image. In art, color tone is a term used to describe the quality or mood of a color, often associated with the use of pigments.