For color displays, gnuplot honors the following resources (shown here with their default values) or the greyscale resources. The values may be color names as listed in the X11 rgb.txt file on your system, hexadecimal RGB color specifications (see X11 documentation), or a color name followed by a comma and an intensity value from 0 to 1. For example, blue, 0.5 means a half intensity blue.
gnuplot*background: white gnuplot*textColor: black gnuplot*borderColor: black gnuplot*axisColor: black gnuplot*line1Color: red gnuplot*line2Color: green gnuplot*line3Color: blue gnuplot*line4Color: magenta gnuplot*line5Color: cyan gnuplot*line6Color: sienna gnuplot*line7Color: orange gnuplot*line8Color: coral
The command-line syntax for these is, for example,
Example:
gnuplot -background coral