Beautiful color images with no color

Quick answer：

This phrase seems to be paradoxical. It is possible that the user is referring to an image that is perceived as beautiful despite its lack of color. In such a case, the concept of 'beautiful' might be based on other elements like composition, texture, or form. If the image is actually monochromatic or grayscale, it would still contain colors, just in varying shades of a single hue. The knowledge related to this could include color theory, aesthetics, and the psychological effects of different colors.