How do I define a custom palette for a contour plot or surface plot?

The primary controls for defining colors for 3D surface or contour plots are accessed in the Surface Specifications dialog box, accessed by clicking the Surface specs button on the Plot: Fitting tab of the Graph Options dialog box. (Display the Graph Options dialog box by double-clicking on the outer background area of the graph.)

For 3D XYZ surface plots (or contour plots, which are projections of 3D surfaces onto a 2-dimensional plane) STATISTICA uses a default color palette consisting of 10 colors ranging from dark green through light greens, yellows, and oranges to shades of red. This color palette can be viewed in the Defining colors area at the bottom of the Surface Specifications dialog box. The number of colors in the palette can be set in the range from 2 to 11 in the Number of defining colors box, and the individual color blocks can be changed by clicking the arrow at the right side of each color window. Note that you can make global changes to the color palette on the Documents/Graphs: Display tab in the Options dialog box.

Color selection by interpolation

The number of color levels required (as determined by the number of minor tickmarks or another option specified in the Get shading levels from box on the Surface Specifications dialog box) is compared by STATISTICA against the number of color levels available in the defined palette. The colors to be applied are then picked across the range of the palette by interpolation between the specified defining colors.