[Color index 0 = white / color index 1 = black]

[Download circular_0.rgb file and put in $NCARG_ROOT/lib/ncarg/colormaps]

Sample NCL script usages:

;---Using the color map to define colors for contours or vectors
  res@cnFillPalette = "circular_0"
  res@vcLevelPalette = "circular_0"

;---Reading the colormap into an N x 4 (RGBA) array
  cmap = read_colormap_file("circular_0")

;---Using the color map to define a color map for the workstation
  gsn_define_colormap(wks,"circular_0")