Understanding Color: Light, Pigments, and Perception

The Fundamentals of Color and Its Application

The study of color encompasses its physical characteristics, how it is mixed, and how it is perceived.

Physical Characteristics of Light

Light is a form of energy, a range of electromagnetic radiation. It can be natural or artificial.

The rainbow is a physical phenomenon demonstrating that white light is composed of seven distinct colors: red, orange, yellow, green, blue, indigo, and violet.

Sir Isaac Newton discovered that white light, when passed through a prism, decomposes into these seven colors of the rainbow.

Light Color: Additive Synthesis

Light color mixing is known as additive synthesis. The three primary colors of light are Red, Green, and Blue (RGB). The mixture of these three produces white light.

Combining any two primary light colors results in secondary colors:

• Cyan (Green + Blue)
• Magenta (Red + Blue)
• Yellow (Red + Green)

Pigment Color: Subtractive Mixing

Pigments are natural or artificial colorants. They are mixed with a binder, which can be more or less liquid, for various applications like painting. For example, oil paint is obtained from natural pigments combined with a binder like linseed oil, while acrylic paint uses natural or artificial pigments with a liquid binder such as latex.

The mixture of pigments is called subtractive mixing.

RGB Color System

The RGB (Red, Green, Blue) system is an additive color model used in technologies and devices that emit light, such as televisions, computer screens, and scanners.

CMYK Color System

The CMYK (Cyan, Magenta, Yellow, Black) system is a subtractive color model primarily used in printing and graphic arts.

Color Perception in Objects

When light strikes an object, some colors are absorbed, and others are reflected. The reflected colors are what we perceive.

A white object reflects all incident light, making it appear white. Conversely, a black object absorbs most incident light, appearing black.

Color Combinations

There are three primary colors for pigments, which are: Yellow, Magenta, and Cyan.

Secondary colors are obtained by mixing two primary pigments in pairs:

• Green (Yellow + Cyan)
• Red (Yellow + Magenta)
• Blue/Violet (Magenta + Cyan)

Tertiary colors are obtained by mixing a primary color with a secondary color.

When arranged in a circle, primary, secondary, and tertiary colors form a color wheel, which visually organizes hues. Colors diametrically opposite on the color wheel are called complementary colors. Key complementary pairs include:

• Red and Green
• Yellow and Violet
• Blue and Orange

Color Qualities and Management

Chromatic colors are universally described by three fundamental qualities:

• Hue
• Lightness (Value)
• Saturation (Chroma)

Hue Variation

Hue refers to the pure spectrum colors, such as red, blue, or yellow, distinguishing one color from another.

Lightness Variation

Lightness, also known as value, describes the degree of a color's brightness or darkness, essentially the amount of white or black it contains.

Saturation Variation

Saturation, or chroma, refers to the purity or intensity of a color. Highly saturated colors appear more brilliant and vivid.

Volumetric Representation of Objects

A primary goal in drawing is to represent three-dimensional objects with a sense of volume. This involves understanding how light interacts with an object's form, creating shadows and highlights that define its perceived volume.