In the color spectrum, where do colors like brown and gray fit in?

Question

most of the colors that we know of are found in a rainbow, but I'm not sure where some of the "plain" colors, like brown, or gray come in.

Answer 1

Black is the absence of color. White is pure light, which contains all the colors. Gray is a combination of white and black. Brown contains all three of the primary colors, red, yellow and blue, mixed together. The rainbow is created when white light is split using a prism, but it doesn't contain the neutrals because they are reflected colors. Any surface or reflected color absorbs the opposite of what it reflects. Black absorbs all the colors, gray some of the light and all of the colors, white reflects all colors.

Answer 2

the color brown is a combination or addition of two primary colors while gray isn't a color but a hue or a substraction of two or more colors i.e.(their wavelengths).