What colors make black? What colors make white?
The way to create black or white depends on whether you’re working with an additive color model (light-based) or a subtractive color model (ink-based).
Additive colors combine to create white.
Light and electromagnetic radiation both create additive color. In this model of color theory, the combination of all colors creates the perception of white. You’ll also hear this model referred to as RGB, because when you work with additive color, you use red, green, and blue as primary colors.
Digital color is additive.
Additive color is used in digital design, because computer screens show hues with colored light. Each pixel is composed of three tiny specks of phosphor, which emit red, green, or blue light when struck by an electron beam. When working with color digitally, like in Adobe Photoshop or Illustrator, your screen uses different combinations of these lights to create all the colors you see. So what is black on a screen? No lit phosphors.
Subtractive colors combine to create black.
The color of pigments and inks are subtractive. Subtractive colors are made of light that’s already passed through material. Painters can combine several colors to make what looks like black paint. Printing also uses subtractive colors; cyan (C), magenta (M), yellow (Y), and key or black (K) are the primary inks used. This is why printable files are called CMYK files.