Right, but color (hue) shouldn&#x27;t require a three-dimensional basis; it is just the frequency domain.<p>If each of the values of a three-dimensional coordinate pair encoded <i>frequency</i>, that triplet could carry information about a mixture of up to three colors. This would require sensors that are not &quot;color blind&quot;.<p>I think that&#x27;s a good summary of the article&#x27;s point.