Colour
This page provides a short introduction to using the colour package on hackage.
The Colour data type
The Colour a
data type and its basic operations are found in the Data.Colour
module. The type variable a
is used to specify the numeric type used for the internal representation of the data. Typically one will use:
Colour Double
You may wish to make a type synonym for this type in your program if you will use it everywhere.
You can always use the colourConvert
to change to a different internal representation type.
Creating colours
A collections of colours given by name can be found in the Data.Colour.Names
module. There is also a readColourName
to convert a string with one of these names into a colour. Be aware that the colour tan
will conflict with the Prelude function unless you hide the Prelude function or import the module qualified.
Another way to make a colour is by specifying an RGB triple. These functions can be found in the Data.Colour.SRGB
library. For example, if you have three Word8
s named red
, green
, and blue
, then
sRGB24 red green blue
will create the colour with those sRGB colour coordinates.
If you have three Double
s named red
, green
, and blue
, then
sRGB red green blue
will produce the colour with those colour coordinates. These Double
should be in the range [0,1] otherwise the resulting colour would be out of gamut (a colour gamut is a collection of representable colours on a device, such as your monitor).
Lastly, sRGB24read
and sRGB24reads
can create colour from string specifications of the form "#00aaff"
or "00aaff"
.