In a continuum of luminance from complete darkness to pure white, the first logical color frequencies are red and orange hues.
The logical answer to the question “After white black and gray, what would be the next logical color?” would presumably be a unanimous--RED. Red has a wide-range of cultural associations, and what it may connote, e.g. life and death (when mixed with black), love and affection (pink) when mixed with white, and myriad other meanings. But regardless of those metaphors, black, white and red have become a way of removing decisions about color and concentrating on form.
