''iocore_alias: <alias> | <red> | <green> | <blue>''

Creates a colour alias for use with [[iocore_colour]] - this will generally be necessary as we can't expect RGB colour mixing to be flat and linear, and to match RGB values used in monitor colour mixing.

  * **alias** is the name of the aliased colour
  * **red, green, blue** are the values for the respective channels for that alias.