Drawing thematic raster datasets that represent categories using a color map

The Colormap renderer is only available if a color map is present with the raster dataset. If a color map does not exist for your raster dataset, you can add one from another raster dataset or import a color map (.clr) or .act file using the Add Colormap tool. Optionally, you can use the Unique Values renderer to apply a color map.

To see if your raster dataset has a color map, in ArcMap, right-click the layer, click Properties, then click the Source tab.

For Esri Grid files, the color map information is stored in a .clr file with the same name. For most other formats, the color map is embedded within the raster dataset.

All renderers have an Import button. Click this button to import symbology from a raster layer file (*.lyr) or a raster layer that is currently in the table of contents. The current renderer must match the renderer of the imported layer. Optionally, you can click the Colormap button to import (or export) a .clr file.

You can also apply the Colormap function with an associated color map file, in ArcMap, using the Add Function button on the Image Analysis window.

Steps:

1. In the table of contents, right-click the raster layer that you want to draw with a color map and click Properties.
2. Click the Symbology tab.
3. Click Colormap.

   You can modify individual colors by double-clicking the rectangular symbol and choosing a new color.

   You can modify the label by entering a new value.

4. Optionally, click the Display NoData as button to symbolize NoData using a color.
5. Click OK.