The discussion explores why the color white is not a mirror despite reflecting all colors. It highlights that white reflects light in a diffused manner, preventing the formation of a clear image, unlike a mirror that reflects light specularly. The conversation also touches on the complexities of light absorption and reflection, noting that not all whites reflect all frequencies equally. Additionally, it delves into human color perception, mentioning how individual differences in retinal cones can affect the way colors are seen. The thread concludes with a mention of tetrachromats, who can distinguish finer color gradients than the average person.