blue2red makes a color map that runs from blue -> cyan ->
yellow -> red.
blue2green makes a color map that runs from blue -> magenta ->
yellow -> green.
green2red makes a color map that runs from green -> cyan ->
magenta -> red
These are double-ramp maps with a sharp transition from cooler colors
to
warmer colors at the midpoint. With proper scaling, this will
highlight the mean, median, etc.
References
Keitt, T. H. (2008) Coherent ecological dynamics induced by large scale disturbance. Nature 454:331-334