Final answer:
People may have begun dreaming in color due to an understanding of the psychological effects of color, the increased ability to distinguish colors, and the cultural meanings attached to various hues. Our physiological processing of colors through opponent process theory and our individual and collective emotional associations with colors likely inform the manifestation of color within our dreams.
Step-by-step explanation:
The question of why people began dreaming in color relates to the multifaceted nature of how humans perceive and interpret colors in waking life. As per Kandinskii, color has a direct influence on the soul, suggesting that our color perceptions could propagate into our dreaming experiences. Discoveries such as the opponent process theory help explain the physiological underpinnings of color perception by describing how retinal ganglion cells and the brain work together to interpret colors. This theory could extend to understanding the transition into color dreams, as the development of color language and discriminative perception in various cultures affect how we process and understand colors, potentially influencing the colors we dream in.
Moreover, the cultural context must be considered, as different societies attribute various meanings, emotions, and significances to colors, which could also affect the content and color palette of our dreams. Therefore, several reasons why people began dreaming in color could include a growing understanding of colors' psychological effects, increased sophistication in the discernment of hues, and complex cultural associations attached to colors. These influence not only our conscious perception but also how we experience dreams.