Each of the API methods that create transient features requires a Feature Code argument. This feature code determines the default color for the feature via associations made in the Color Index File. Each line of this file assigns a color index to a feature code, except for the last line which defines the default color index. The color index refers to an entry in the Color Map File which assigns a color to that index. Any feature code not assigned in this file will be assigned the color associated with the default color index.
The Color Index File that comes with the SICOM installation is an example. The developer may edit this file to add or remove color Index / feature code associations. Just make sure that any index entered can be found in the Color Map File. A color index file must exist and be referenced by the uslxcolor environment variable, regardless of whether any transient features are to be created.