inputIdThe input slot that will be used to access the value.
labelDisplay label for the control, or 'NULL for no label.
valueInitial value (can be a colour name or HEX code)
showColourWhether to show the chosen colour as text inside the input,
as the background colour of the input, or both (default).
paletteThe type of colour palette to allow the user to select colours
from. square (default) shows a square colour palette that allows the
user to choose any colour, while limited only gives the user a
predefined list of colours to choose from.
allowedColsA list of colours that the user can choose from. Only
applicable when palette == "limited". The limited palette
uses a default list of 40 colours if allowedCols is not defined. If
the colour specified in value is not in the list, the default colour
will revert to black.
allowTransparentIf TRUE, enables a slider to choose an alpha
(transparency) value for the colour. When a colour with opacity is
chosen, the return value is an 8-digit HEX code.
returnNameIf TRUE, then return the name of an R colour instead
of a HEX value when possible.
closeOnClickIf TRUE, then the colour selection panel will close
immediately after selecting a colour.