NCL
The NCL (NCAR Command Language) is an open-source interpreted language designed specifically for scientific data analysis and visualisation.
The source package includes a number of colour-tables, translated into discrete (piecewise constant) gradients.
amwg
amwg blueyellowred
BkBlAqGrYeOrReViWh200
BlAqGrYeOrRe
BlAqGrYeOrReVi200
BlGrYeOrReVi200
BlRe
BlueDarkOrange18
BlueDarkRed18
BlueGreen14
BlueRed
BlueRedGray
BlueWhiteOrangeRed
BlueYellowRed
BlWhRe
BrownBlue12
Cat12
cosam
cosam12
GrayWhiteGray
GreenMagenta16
GreenYellow
hotcold 18lev
hotcolr 19lev
mch default
nrl sirkes
nrl sirkes nowhite
OceanLakeLandSnow
perc2 9lev
percent 11lev
posneg 1
posneg 2
prcp 1
prcp 2
prcp 3
precip 11lev
precip2 15lev
precip2 17lev
precip3 16lev
precip4 11lev
precip4 diff 19lev
precip diff 12lev
precip diff 1lev
radar
radar 1
rh 19lev
spread 15lev
StepSeq25
sunshine 9lev
sunshine diff 12lev
t2m 29lev
tbr 240 300
tbrAvg1
tbrStd1
tbr stdev 0 30
tbr var 0 500
tbrVar1
temp 19lev
temp diff 18lev
temp diff 1lev
thelix
topo 15lev
ViBlGrWhYeOrRe
wgne15
WhBlGrYeRe
WhiteBlue
WhiteBlueGreenYellowRed
WhiteGreen
WhiteYellowOrangeRed
WhViBlGrYeOrRe
WhViBlGrYeOrReWh
wind 17lev
wxpEnIR