Color Theory Notes

Textile Coloration

What is Color: Color is the sensation arising from the activity of the retina of the eye.
Human vision relies on light-sensitive cells in the retina.
Two types of sensors:
- Rods: Work at low intensity, cannot resolve sharp images or color.
- Cones: Resolve sharp images and color, require higher light levels.

We can detect three visible colors: Red, Blue, and Green.
These are called additive primaries.
These three colors mixed in our brain create all other colors.
Red is at the lower end of the spectrum with a higher wavelength but lower frequency.
Violet is at the top end of the spectrum with a lower wavelength and higher frequency.

Sunlight is a familiar source.
To see colors from white light, use a prism.
Light splits into seven colors via refraction.
Refraction is caused by a change in speed when light changes medium.
Red has a wavelength around 700 nm, while Violet has a wavelength around 400 nm.

Waves of Energy
Positive and negative charges vibrate, producing electromagnetic waves at 186,000 miles per second (speed of light).
Each wave has a different wavelength and speed of vibration, forming the electromagnetic spectrum.

Frequency: The number of complete waves passing a point each second.
Red has a frequency of around 430 trillion vibrations a second.
Violet has a higher frequency, so each violet wave passes a point quicker than red.

Primary Color (RYB/Subtractive Model): Red, Yellow, and Blue.
In traditional color theory, primary colors cannot be formed by combining other colors; other colors are derived from them.
Secondary Color: Green, Orange, and Purple.
Created by mixing two primary colors.

Tertiary Color: Mixing primary and secondary colors.
Examples: Yellow-orange, red-orange, red-purple, blue-purple, blue-green, and yellow-green.
Two-word names indicate a mix of primary and secondary colors.

Warm & Cool Color: The color circle divides into warm and cool colors.
Warm colors (red, yellow, oranges) are vivid and energetic, creating warmth, activity, and excitement.
Cool colors (blue, purple, green) give a calm, soothing impression, creating coolness, calmness, and relaxation.

Natural color: White, black, brown, tan cream and gray are considered to be neutral. They are not found in color wheel.
Complementary Color Schemes: Colors opposite on the color wheel (e.g., red and green).
High contrast creates a vibrant look, especially at full saturation.

Color Mixing Theory: Visible colors are produced by combining three primary colors.
Two theories:
- Additive theory
- Subtractive theory

Additive Theory: Also called RGB theory.
Color is created by adding light (red, green, blue) to a dark background.
TV screens and projectors use RGB as primary colors.
Red + Green = Yellow
Green + Blue = Cyan
Blue + Red = Magenta
Red + Blue + Green = White
Additive color processes generate images composed of red, green, and blue light.
The 3 primaries in light are red, blue, and green, because they correspond to the red, blue, and green cones in the eye.
Example shows how the light from red, green and blue flashlights would appear if shone on a dark wall.

Subtractive Theory: Also called CMYK theory.
Subtractive color has three primary colors: Cyan, Magenta, and Yellow (CMY).
White is the absence of color; black is the combination of color (imperfect system).
"Key" refers to black, hence CMYK.
Subtractive color synthesis: creating color by mixing pigment colors (paint or ink).
Used in art and design.
Subtractive color processes work by blocking parts of the spectrum.
The idea is to reduce the amount of undesired color reaching the eye.

In subtractive color, a yellow image lets red and green reach the eye, blocking blue.
Additive secondaries become printer's subtractive primaries because each additive secondary reflects two additive primaries and absorbs one.

Saturation or Chroma: Defines the brilliance and intensity of a color.
The brightness or dullness of hue.
When a pigment hue is "toned," white and black (grey) are added to reduce saturation.

Lightness Value: The dimension of lightness/darkness.
Describes the overall intensity or strength of the light.
If hue is a dimension around a wheel, then value is a linear axis through the middle.