Color routines
| color_index_to_rgba | Converts an absolute color index to its equivalent RGBA quadruplet |
| ColorNegDashZeroPosContour | Sets the negative contours to dashed, and colors the negative, positive, and zero contours to user-specified colors. |
| ColorShadeLeGeContour |
Shades contour regions given low and high values and two colors. (Deprecated. Use gsn_contour_shade.) |
| draw_color_palette | Draws the given colors or color map as a series of filled boxes. |
| get_color_rgba | Chooses an RGB triplet or RGBA quadruplet for a scalar value, given a color map and a range of values. |
| GetFillColor | Chooses a color from a group of RGB triplets based upon a secondary scalar field (deprecated version). |
| GetFillColorIndex | Chooses from a list of color table indices based upon a secondary scalar field (deprecated version). |
| gsn_contour_shade | Shades contour regions given low and/or high values using colors or patterns. |
| gsn_define_colormap | Defines a color map for the given workstation. |
| gsn_draw_colormap | Draws the current color map for the given workstation. |
| gsn_draw_named_colors | Draws the given list of named colors. |
| gsn_merge_colormaps | Merges two color maps and sets this as the color map for the given workstation. |
| gsn_retrieve_colormap | Retrieves a color map for the given workstation. |
| gsn_reverse_colormap | Reverses the color map for the given workstation. |
| hlsrgb | Converts HLS color values to RGB. |
| hsv2rgb | Maps values from the HSV color model to the RGB color model (deprecated). |
| hsvrgb | Converts HSV color values to RGB. |
| namedcolor2rgb | Returns the RGB triplets of the given list of named colors. |
| namedcolor2rgba | Returns the RGBA quadruplets of the given list of named colors. |
| NhlFreeColor | Removes one or more color entries from one or more workstations. |
| NhlGetNamedColorIndex | Returns color map indexes that match the given color names in the color maps of the given workstations. |
| NhlIsAllocatedColor | Queries a list of workstations to determine whether or not the given color indexes have been allocated. |
| NhlNewColor | Allocates new workstation color indexes. |
| NhlPalGetDefined | Returns a list of available color maps. |
| NhlSetColor | Sets the colors for a given list of color indexes and workstations. |
| read_colormap_file | Reads an NCL system colormap file or a user-defined colormap. |
| rgbhls | Converts RGB color values to HLS. |
| rgbhsv | Converts RGB color values to HSV. |
| RGBtoCmap | Reads a text file of RGB triplets and converts them to a colormap. |
| rgbyiq | Converts RGB color values to YIQ values. |
| setColorContourClear | Sets the color contours between two given levels to transparent. |
| span_color_indexes | Given the number of desired color values, return an array of indexes that nicely span the given color map. |
| span_color_rgba | Given the number of desired color values, return an array of RGB triplets or RGBA quadruplets that nicely span the given color map. |
| span_named_colors | Returns an RGB array that is a span between given list of named colors. |
| yiqrgb | Converts YIQ color values to RGB. |