Red, green, and blue-violet light can be combined to create any color of the spectrum. This has been interpreted as supporting:

The concept of combining red, green, and blue-violet light to create any color of the spectrum aligns with the trichromatic theory of color vision. This theory posits that the human eye has three types of receptors, each sensitive to different wavelengths corresponding to these primary colors. When these three colors of light are combined in various ways, they can produce a wide range of colors that we perceive. This is the foundational principle behind additive color mixing, which occurs when different colors of light are mixed, as seen in technologies like computer screens and televisions.

In contrast to this, the opponent-process theory focuses on the idea that our perception of color is controlled by opposing pairs, such as red-green and blue-yellow. While this theory explains some aspects of color perception, it does not account for the mixing process illustrated by trichromatic theory. Feature detection theory pertains more to the perception of specific features within a visual stimulus, rather than the mixing of colors themselves. Lastly, color constancy theory deals with our ability to perceive colors as relatively constant even under varying lighting conditions, which is unrelated to the color combination aspect discussed in the question. Thus, the trichromatic theory is the correct interpretation of how red, green, and blue-violet light can create