The Color Theory includes many definitions, concepts and design applications. It is a body of practical guidance to color mixing and the visual impacts of specific color combinations. The Color Theory principles first appeared in the writings of Leone Battista Alberti (circa 1435) and the notebooks of Leonardo da Vinci (circa 1490). Here are the basic concepts.

Additive and Subtractive Colors

The foundations of pre-20th-century Color Theory were built around "pure" or ideal colors, characterized by sensory experiences rather than attributes of the physical world. This has led to a number of inaccuracies in traditional Color Theory principles that are not always remedied in modern formulations. The most important problem has been a confusion between the behavior of light mixtures and the behavior of pigment mixtures. First we have got to know that there are two kinds of color mixing, Additive and Subtractive. While 'Additive Colors' are formed by combining light, 'Subtractive Colors' are created by combining color pigments.

Additive Colors: In real life colors are nothing but… Light! Starting from the Black, which is really the absence of light, the primary additive colors, Red, Green and Blue, blend to make all the others, lighter and lighter every time. Light is perceived as white by humans when all three cone cell types of the eye are simultaneously stimulated by equal amounts of Red, Green, and Blue light. It is called 'Additive Colors' because we are 'adding' lights to create color. A color television, computer monitor and stage lighting all demonstrate this process. By mixing two additive primaries, we produce additive secondary colors that match the primary colors in subtractive color mixing. Click and drag the circles around to mix the colors:

By mixing together additive primaries in different proportions, you can make just about any color. Adjust the percentage of the individual Red, Green and Blue:

Subtractive Colors are the ones made by pigments which we use to paint. The primary subtractive colors, Magenta, Yellow and Cyan, are of paramount importance to the color printing and photography industry. Color pigments absorb or "subtract" certain wavelengths of color from the White background, and allow others to be reflected. We start with a White surface, and blend the subtractive primary colors (Magenta, Yellow and Cyan) to get all the others. The more colors we mix together, the darker the new one will be. If we blend them all, we get Black. By mixing two subtractive primaries, we produce subtractive secondary colors that match the primary colors in additive color mixing. Click and drag the circles around to mix the colors:

By mixing together subtractive primaries in different proportions, you can make just about any color. Adjust the percentage of the individual Magenta, Yellow and Cyan:

From now on, we will focus on the subtractive mixing process, which is the one we use in painting, because painters use pigments. We will also rename and replace Magenta and Cyan with Red and Blue to make it more simple. This is the universally accepted way Primary Colors are most commonly represented, and the way that Color Wheel is taught to most people today. The Color Theory was originally formulated in terms of these three primary colors only (Red, Yellow and Blue) because they were believed capable of mixing all other colors. Please note that many disagree with this premise nowadays.

The Color Wheel   

The typical artists' paint or pigment Color Wheel is a color circle, based on Red, Yellow and Blue, that is traditional in the field of art. Sir Isaac Newton developed the first circular diagram of colors in 1666. Color wheels show how colors are related, and help artists remember how to mix and think about pigments. In this circular chart, the Primary Colors (Red, Yellow and Blue) are placed alternately. In between two Primary Colors there is the color which results from blending them: Orange is between Yellow and Red, Green is between Yellow and Blue, and Purple is between Blue and Red. These new colors created from two primary colors are known as 'Secondary Colors'.

  Neutral colors, such as browns and grays, containing all three of the primary colors, are known as 'Tertiary Colors'. They are created by mixing either all three primary colors or a primary and secondary color. In this last case, they are also called 'Intermediate Colors'. An example of intermediate color is Yellow-green.

The 'Adjacent Colors' (also called 'Analogous Colors') are the colors located next to each other on the Color Wheel. For example Green and Yellow or Purple and Red. The two colors on opposite sides of the color wheel are known as 'Complementary Colors'. The complementary color of a primary color (Red, Yellow and Blue) is the color you get by mixing the other two. So the complementary color for Red is Green, for Yellow is Purple and for Blue is Orange.

 According to traditional Color Theory derived from paint mixtures, Yellow mixed with Violet, Orange mixed with Blue, or Red mixed with Green produces an equivalent Gray. These contrasts form the basis of law of color contrast: colors that appear together will be altered as if mixed with the complementary color of the other color. Thus, a piece of yellow fabric placed on a blue background will appear tinted orange, because orange is the complementary color to blue. Also, the complementary colors when placed next to each other appear brighter. This effect has been used extensively in Painting art, most of times in a subtle way, but not always. The Impressionist and Neo-Impressionist painters used it in a marked way; the Post-Impressionist, Expressionist, and especially the Fauvist, used complementary colors in a violent way.

"Woman with a Hat (detail)" (1905) Henri Matisse.

Cool and Warm Colors

The distinction between 'Warm Colors' and 'Cool Colors' has been important since at least the late 18th century and is still used in design practices today. Blues, greens, and purples are considered cool colors. They appear on one side of the color wheel. On the opposite side, reds, oranges, and yellows are considered warm colors. Psychologically, cool colors are said to be calming and depressive, while warm colors are said to be stimulating and passionate.

Optically, cool colors appear to recede: in Aerial Perspective, cool colors are said to move away from you, while warm colors appear to come towards you.

Achromatic colors

Any color that lacks strong chromatic content is said to be unsaturated, achromatic, or near neutral. Pure achromatic colors include Black, White and all grays; near neutrals include browns, tans, pastels and darker colors. Near neutrals can be of any hue or lightness.

Neutrals are obtained by mixing pure colors with either White or Black, or by mixing two complementary colors. In Color Theory, neutral colors are colors easily modified by adjacent more saturated colors and they appear to take on the hue complementary to the saturated color. Next to a bright Red couch, a Gray wall will appear distinctly greenish.

Black and White have long been known to combine well with almost any other colors; Black increases the apparent saturation or brightness of colors paired with it, and White shows off all hues to equal effect.

Hue, Shade, Tint and Tone

• 'Hue' is the actual color of something, such as Red, Green, or Blue. What we generally, but less technically correct, call 'color'. Humans can perceive over 2.8 million different hues. Click here to see some color names displayed alphabetically - place the mouse over any of them to see which hue it is.

• 'Shade' is any color that has been mixed with Black to make it darker:

• 'Tint' is any color that has been mixed with White to make it lighter:

• 'Tone' is the degree of lightness or darkness of a color, rather than what the actual color is:

 When mixing colored light (additive color models), the achromatic mixture of spectrally balanced Red, Green and Blue is always White. But when we mix the pigments in paint mixtures, a color is produced which is always darker and lower in saturation, than the parent colors. This moves the mixed color toward a neutral color, a Gray or near-Black.

In painting, lightness is adjusted through mixture with White, Black or a color's complement. It is common among some painters to darken a color by adding Black paint or lighten a color by adding White paint. However it is not always the best way for representational painting, as an unfortunate result is for colors to also shift in hue. For instance, darkening a color by adding Black can cause colors such as Yellow, Red and Orange, to shift toward the greenish or bluish part of the spectrum. Lightening a color by adding White can cause a shift towards Blue. A good advice when darkening a color is to use its complementary color in order to neutralize it without a shift in hue. Also, when lightening a color this hue shift can be corrected with the addition of a small amount of an adjacent color to bring the hue of the mixture back in line with the parent color (e.g. adding a small amount of Orange to a mixture of Red and White will correct the tendency of this mixture to shift slightly towards the blue end of the spectrum).

Painting Techniques

A painting technique is a process of applying the colors, the pigments, onto a surface. The material used by an artist to produce a work of art, chiefly the substance that binds the pigment in paint, is what names each technique. In acrylic paints it is a synthetic substance. In oil paints, it is a natural oil such as poppy oil. In tempera, it is egg yolks. The most important painting techniques are:

• oil paint

• watercolor

• fresco

• pastel

• tempera

• gouache

• acrylic paint

• encaustic

Besides these techniques, where each piece of art is produced individually, artists have used other techniques which allow them to produce a large number of artwork, or prints, at the same time. In some cases, such as the lithographic process, a deep knowledge of the Color Theory is required. These are the most important methods of printmaking:

• etching

• engraving

• lithography

• serigraphy

In addition, the term 'painting technique' may refer to a particular way of applying paints onto a surface, or how they are rendered, rather than the medium that is used. In some of these techniques, such as 'pointillism' and 'dry brush', colors are created through the knowledge of Color Theory and how the eye perceives colors that are painted next to each other (optical mix).

• action painting

• alla prima

• cloisonism

• chiaroscuro

• dry brush

• frottage

• glaze

• hatching

• impasto

• pointillism

• scrumbling

• sfumato

• spattering

• stippling

• wash

• wet-on-dry

• wet-on-wet

Jackson Pollock