Plotting with filledcurves can be further customized by giving a fillstyle
(solid/transparent/pattern) or a fillcolor. If no fillstyle (fs)
is given in the plot command then the current default fill style is used.
See set style fill (p. ). If no fillcolor (fc) is given in the plot command,
the usual linetype color sequence is followed.
The {{no}border} property of the fillstyle is honored by filledcurves mode
closed, the default. It is ignored by all other filledcurves modes.
Example:
plot 'data' with filledcurves fc "cyan" fs solid 0.5 border lc "blue"