Recently a post on the importance of light and color in how people "see" was posted which generated a thought. What becomes important in an image if color is removed. To see what happens the image below was created of an early morning cloudscape over the Peloncillo mountains. When the colors are converted to grayscale the result is an image where differences in texture and contrast seem to dominate. Rather than the wavelength of reflected light being a dominate component of the photograph (a phenomena external to the camera's CMOS chip) it is the internal differences within the image itself that become important to me as a viewer. Visually exploring the color original my eye first focuses on the blue sky and not the clouds, while in the black and white image my eye is drawn to the clouds and the differences in contrast then in texture. So perhaps underlying the differences in color are the important differences in contrast and texture which helps make a photograph interesting to a viewer.
Original multi-image panorama in color as a starting point.
Final product, an early morning cloudscape in black and white