How are Secondary Colors produced?

Secondary colors are produced by mixing two primary colors. This process relies on the foundational color theory that identifies the three primary colors—red, blue, and yellow. When two of these primary colors are combined in equal parts, they create a secondary color: red and blue mix to form purple, blue and yellow produce green, and red and yellow result in orange. Understanding this concept is crucial for any stylist or colorist, as it helps in predicting the outcome of color mixtures and achieving desired results on the hair.

The other options do not align with the definition of secondary colors. For instance, blending one primary and one neutral color wouldn't result in a secondary color, as neutral colors do not significantly contribute to the hue aspect. Similarly, using a lightener on primary colors or heating primary colors together does not apply to color mixing as defined by traditional color theory.