Gnuplot user-defined color schemes

As already explained in this blog entry, this is the way to define color macros:

set macros
redgreenblue_small = "defined (\
                   0  0.0 0.0 0.5, \
                   1  0.0 0.0 1.0, \
                   2  0.0 0.5 1.0, \
                   3  0.0 1.0 1.0, \
                   4  0.5 1.0 0.5, \
                   5  1.0 1.0 0.0, \
                   6  1.0 0.5 0.0, \
                   7  1.0 0.0 0.0, \
                   8  0.75 0.0 0.0, \
                   9  0.5 0.0 0.0, \
                   10  0.25 0.0 0.0, \
                   11  0.0 0.0 0.0 )"

To use them in gnuplot you simply type:

set palette @redgreenblue