Oce CS520, User Manual

Page: 174 / 472

About Colours
7-174
About Colours
RGB and CMYK Models
Have you ever wondered why the world surrounding us appears coloured to our
eyes?
Light is electromagnetic waves with wavelengths between about 380 - 780 nm, also
called visible rays. The wavelengths of visible rays can be separated into the
rainbow colours violet, indigo, blue, green, yellow, orange, and red, from the
shortest wavelength in order. When all the wavelengths of the visible rays strike your
eye at the same time, white colour is perceived. We see the objects in colour
because they reflect or transmit visible light of different wavelengths or frequencies.
The colours separated from visible light are called primary colours. Primary colours
cannot be produced from other colours. These colours, however, can be combined
to make up any other colour (colour mixture).
The colour mixture provides two different types, three primary colours of light and
three primary colours of pigment. The three primary colours of light are called
additive colour mixture, and the more colours are added, the brighter it will be.
Mixing red (R), green (G), and blue (B) coloured lights, various colours can be
created.
Colour
Reflection
Light
Electromagnetic wave
(m)
(nm)
Visible rays
White
light
Slit
Prisma