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About NCL color tables

There are a large number of predefined color tables available. The default color table has 32 colors.

If you have a color table that you use exclusively, you can set this in your .hluresfile so that it becomes the default every time you run NCL.

You can create your own color table file and place it where NCL can load it directly. You can also use predefined named colors, or create your own color table inside an NCL script using an n x 3 floating point array. For some examples, see the color page in the application examples.

Of related interest, there's an interesting article on improving color maps for scientific visualizations entitled "The End of the Rainbow? Color Schemes for Improved Data Graphics". Click on the PDF file to download the article, or view some of the PNG files for comparisons of color maps.

Groupings

• rainbow
• small ( < 30 colors)
• 2 color gradiated
• tables for help with color blindness and color deficient viewers
• white in middle
• gray scale
• misc

Application Examples

• using named colors
• reverse color table
• CMYK
• using RGB triplets
• HSV
• changing foreground/background colors
• retrieving the RGB triplets of the colormap

Code Snippets

    gsn_define_colormap(wks,"gui_default")

    setvalues wks 
      "wkColorMap" : "temp1"
    end setvalues