A method and an associated device construct a uniform color space from raw RGB data without going through any intermediate color space, such as CIEXYZ. A direction and a scale of each of first, second and third perceptual color axes may be determined based at least in part on the characteristics related to the imaging device, such that a first perceptual color axis correlates with lightness, a second perceptual color axis correlates with yellow-blue color variations, and a third perceptual color axis correlates with red-green color variations. The second perceptual color axis may be substantially aligned with typical daylight variation.