Product Design Sketching

Chromatic Theories

Color Spectrum

The range of colors seen by human eye is the “visible color spectrum”

Color Models

RGB Model Additive model (as that

of light) The 3 primary colors add

up to form the white color

CYMK Model Subtractive model (as

that of paint pigment) Cyan, Yellow, Magenta

and Black add up to become the black color

Basic Attributes of a Color

A color can be denoted by its HSB value, i.e. the 3 attributes:

Hue Tint of the color Location of the color in

the color spectrum Saturation

Intensity or amount of color pigment

Brightness / Lightness Light value of the color Intensity or amount of

light

HSB Values

You may use the colour picker of Adobe PhotoShop to identify the HSB values of your colour pencil

Adjust hue and saturation

Adjust brightness

Saturation vs. Brightness

saturation

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Colour Physiology and Psychology

Our perception of colour is governed not only by Physics but also by the

biological structure of our eyes and the wiring of our brain

Colour Perception

The color of an object being seen is determined by:

Local color (of the object’s surface material)

Ambient color (of the light source)

Reflected color (from another object’s nearby)

Color Perception

What we see is not ‘real’ but ‘perceived’

Colour Perception

Dithering is a technique used in computer graphics to create the illusion of color depth with a limited color palette

In a dithered image, colors not available in the palette are approximated by a diffusion of colored pixels from within the available palette. The human eye perceives the diffusion as a mixture of the colors within it.