Principles on Color Theory
All colors we see are derived from three colors: Red, Yellow, and Blue. These are your Primary Colors:
Red
Yellow
Blue
Secondary Colors are the presence of two Primary Colors mixed together:
Yellow + Red = Orange
Yellow + Blue = Green
Blue + Red = Purple
Neutralizing

When all three Primary Colors are present, they “neutralize.” Neutral Colors are often referred to with terms like “brown,” “beige,” “tan,” and “blonde.”
In makeup application, “neutralizing” and “concealing” are terms often considered synonymous. But, concealing is an application of makeup that uses color theory to neutralize unwanted tones, whereas neutralizing is a color theory technique that can be used to conceal, but can also be used to adjust undertones and overtones for all kinds of potential applications (foundations, highlights, eye shades, etc.).