The discussion revolves around the scientific definition of color, primarily focusing on the distinction between color as a perceptual experience and wavelength as a physical measurement. Alexander asserts that colors are defined by specific wavelengths (red at 0.65 um, green at 0.55 um, and blue at 0.48 um), emphasizing that perception is subjective and not scientifically valid. Others, including RageSk8 and wuliheron, argue that color is fundamentally tied to human perception, suggesting that wavelengths alone do not encompass the full experience of color. They highlight that color is a mental construct assigned to specific wavelengths, which can vary among individuals and species, such as cats perceiving ultraviolet light. The conversation also touches on the limitations of human perception and the role of scientific instruments like spectrometers in measuring wavelengths objectively. The debate highlights the philosophical implications of how color is defined and perceived, suggesting that while wavelengths are objective, color remains a subjective experience influenced by individual perception.