Studies on the effectiveness of cranberry juice for preventing or treating UTIs have produced mixed results. The red berry contains a tannin that prevents E. coli bacteria - the most common cause of urinary tract infections - from sticking to the walls of the bladder, where they can cause infection.
primary color for pigments - any of three pigments from which all colors can be obtained by mixing; the primary colors for pigments are red, blue, and yellow. primary colour for pigments. primary color, primary colour - any of three colors from which all others can be obtained by mixing.
All of the wavelengths present in visible light form colorless white light when they are combined, but can be refracted and dispersed into their individual colors by means of a prism. The colors red, green, and blue are classically considered the primary colors because they are fundamental to human vision. All other colors of the visible light spectrum can be produced by properly adding different combinations of these three colors. Moreover, adding equal amounts of red, green, and blue light produces white light and, therefore, these colors are also often described as the primary additive colors.