This in primarily an internal openair function to make it
easy for users to select particular colour schemes, or
define their own range of colours of a user-defined length.Each of the pre-defined schemes have merits and their use
will depend on a particular situation. For showing
incrementing concentrations e.g. high concentrations
emphasised, then "default", "heat", "jet" and "increment"
are very useful. See also the description of
RColorBrewer
schemes for the option scheme
.
To colour-code categorical-type problems e.g. colours for
different pollutants, "hue" and "brewer1" are useful.
When publishing in black and white, "greyscale" is often
convenient. With most openair functions, as well as
generating a greyscale colour gradient, it also resets
strip background and other coloured text and lines to
greyscale values.
Failing that, the user can define their own schemes based
on R colour names. To see the full list of names, type
colors()
into R.