Design Principles - Colour Theory - Systematic Colour

Understanding colour:

HUE + TONE + SATURATION =  CHROMATIC VALUE

HUE defines pure colour in terms of RGB and is measured by its location on a colour wheel:

TONE - Adding white to a hue = Shade

              Adding grey/black to a hue = Tint

Starting with R:255 G:0 B:0 I created 5 shades reducing luminance.

SATURATION - 'Taking colour out of a colour'

Three aspects of Colour perception:

http://monoskop.org/images/4/46/Itten_Johannes_The_Elements_of_Color.pdf

The eye contains two types of cones:

Rods allow the eye to perceive shades of grey and black

Cones allow the eye to perceive colour

The three types of cones perceive R,G and B - A mix of these allow any colour within the spectrum of visible light.

Similar to the agreement we have about the identification of glyphs within a typeface, the whole human race has an agreement about the identification of colour, for example:

We agree that this mix of light is red.

 Physiology is a mix of the physical and psychology of colour perception:

Varying amounts of RGB stimulates each cone creating our spectrum of visible light.

A visual comparison of the colours perceived with varying eye compartments.  

Systematic Colour

Johannes Itten

I downloaded the PDF here: http://monoskop.org/images/4/46/Itten_Johannes_The_Elements_of_Color.pdf

Itten Colour wheel:

Red, blue and yellow make the primary colours.

Green, Purple and Orange make the secondary colours.

Tertiary colours combine one primary and one secondary colour, for example Green - Yellow is in between green and yellow.

A key to identifying colours on the wheel. 

We call two colors complementary if their pigments, mixed together, yield a neutral gray-black…Two such colors make a strange pair. They are opposite, they require each other. They incite each other to maximum vividness when adjacent; and they annihilate each other, to gray-black, when mixed — like fire and water. 

- Johannes Itten

Complementary colours.

These gradients showing each colour becoming less saturated meeting in the middle with a colourless grey.

After a lot of confusion, I finally understood Saturation, I have not added black to the green, I have taken green away from the green by reducing its value from 255.

RGB is additive. CMYK is subtractive.

Cyan (C), Magenta (M), Yellow (Y) and Black (K)

Conversion from RGB to CMYK

A printer prints each ink starting from light to dark, so YMCK

CcMmYK used in inkjet printers for photo printing creates less contrast of the halftone dots using a lighter tone of Magenta and Cyan.