Adobe Photoshop/Spot Color

Spot Color refers to a color that does not go through the CMYK process to obtain color values. Instead, each color in a document is creating using that exact color, not a mixture of CMYK halftone values. Spot colors are used in offset printing, or where a particular color (like in a logo) must be precise.

Example:

The color dark blue is a mixture of CMYK values. (Image from Photoshop)

A similar looking spot color, which uses Pantone colors, is a solid color instead of a CMYK combination. (Image from Photoshop)