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.
Yellow, magenta and cyan are the primary pigment colors, red,  green and blue are the secondary pigment colors. Light uses the  opposite colors, the secondary pigment colors become the primary  light colors. Red, yellow and blue are not the primary colors in  pigment or in light.