The color white is sometimes referred to as 'clear' or transparent as in no visible color because clear/white is undifferentiated (not refracted). In the Russell materials and in Hughes' Harmonies of Tones and Colors white is considered the central or source color within the visible spectrum.
The division of sexless Oneness into pairs could not be a part of Nature's process without also dividing the Oneness of Light. God's Magnetic Light is white because it is still. It has no tensions or strains in it, for it is not divided. It is invisible to the senses because it has no motion in it. The moment motion begins the Light of the Creator's energy is divided into pairs which multiply their red and blue intensities in the ratio of their extension from their cathode beginnings, just as electric potential multiplies its intensity for the same reason. [Atomic Suicide, page 92]
"The master-tone of each octave is the inheritance of the original motion of the thinking process of Mind. These master-tones are the "inert gases" which are classified in the zero group of the Mendeleef table.
"The master-tones which represent a state of motion-in-inertia and are the inert gases, bear the same relationship to the elements that white bears to the colors. They are a registration of them all. White is not included in the spectrum, it has no place there. The inert gases should not be included in the elements. They have no place there. Of this more shall be written later in its proper place." [Russell, The Universal One]
The perfect color, of course, is white, and this is what we all are striving for. If our souls were in perfect balance then all our color vibrations would blend and we would have an aura of pure white. Christ had this aura, and it is shown in many paintings of Him, particularly those which depict Him after the resurrection. You recall that He said at the tomb, "Touch me not for I am newly arisen." He meant that as a warning, I think, for the vibration of His being must at that time have been so powerful that anyone putting a hand on Him would have been killed - shocked as if by (a) live wire. [Auras - An Essay On The Meaning Of Colors; A.R.E. Press, 67th & Atlantic Ave., Virginia Beach, Va. 23451, 1972]