response: I am not sure but red is a primary color on the CMYK and RGB color models.
original_response: I am not sure but red is a primary color.
history: Red is such a pretty color, don't you think? I don't lean one way or the other, I just know that it has a 625 to 740 nanometer dominant wavelength. Oh wow! That's a new one for me! How many different shades are there?
knowledge: It is a primary color in the RGB color model and the CMYK color model, and is the complementary color of cyan.