Mr Dave's Colour Challenge

Computer screens make colour by mixing three different colours of light :

Red, Green and Blue.

This system is called RGB.

Objects on a web page can have millions of different colours. That is because for red, green and blue, the computer can remember 256 different shades ranging from black to the pure colour - as shown below.

Colour is saved in files by storing the amount of each colour used.  256 different amounts can be remembered for each colour and so each colour is given a value from 0 to 255. As there can be 256 shades of red, green and blue, this makes:

256 x 256 x 256 = more than 16 million possible colours

This square has values Red-125, Green-0, Blue-0  
This square has values Red-125, Green-125, Blue-0  
This square has values Red-125, Green-125, Blue-125  
If all the values of R,G and B are similar the colour made is grey. 

Try to match the colour of the box on the left to the box on the right by adjusting the values for R, G and B.




Some programs may ask you to select which colour you want by selecting values for hue, saturation, and brightness.

Hue is what colour is, e.g. blue, red, pink, orange, brown etc.

Saturation is how pure the colour.  High saturation gives a pure colour such as bright red and low saturation gives a greyer tone.

Brightness (or Luminosity) is how light the colour is.  Low brightness gives a dark shade and high brightness gives a light shade.