According to one hypothesis, the hypertensive effect of alcohol is from a chronic state of alcohol withdrawal in frequent, heavy drinkers, but there is much evidence in favor of a direct effect of alcohol on BP.
Color Perception. The properties of color which are inherently distinguishable by the human eye are hue, saturation, and brightness. While we know that the spectral colors can be one-to-one correlated with light wavelength, the perception of light with multiple wavelengths is more complicated. It is found that many different combinations of light wavelengths can produce the same perception of color. This can be put in perspective with the CIE chromaticity diagram. The white or achromatic point E can also be achieved with many different mixtures of light, e.g. with complementary colors.
Colors exist in the larger context of human vision. Consider the fact that there are three parts to the process of the perception of color. 1. The medium - The color as it exists as a pigment/colorant (such as the color of a tangible object) or as light (such as the color of an image on a television screen).