The color measurement instrument includes an illumination system and a sensing system. The illumination system is composed of a light emitting element and a light pipe. The light pipe has an incident surface at an illuminating end of the light emitting element and an ejected surface adjacent to a sensing platform of a sensing system. The sensing system includes a light collection device and a sensing platform for disposing a testing object. The light collection device includes an aperture stop for adjusting the shape of a light spot on a color sensor, a light collection lens set for detecting and projecting an image of a testing object on the sensing platform, a field stop for separating a light from an area, an uniform lens set for spreading the image on the field stop, and a color sensor for capturing and analyzing the color to adjust the brightness.