In the gEDA/gaf schematic and symbol file format colors are specified via an integer index. The relationship between integer and color is based on object type. Each object type typically has one or more colors. Here is a table of color index to object type:
| Index | Object type |
|---|---|
| 0 | BACKGROUND_COLOR |
| 1 | PIN_COLOR |
| 2 | NET_ENDPOINT_COLOR |
| 3 | GRAPHIC_COLOR |
| 4 | NET_COLOR |
| 5 | ATTRIBUTE_COLOR |
| 6 | LOGIC_BUBBLE_COLOR |
| 7 | DOTS_GRID_COLOR |
| 8 | DETACHED_ATTRIBUTE_COLOR |
| 9 | TEXT_COLOR |
| 10 | BUS_COLOR |
| 11 | SELECT_COLOR |
| 12 | BOUNDINGBOX_COLOR |
| 13 | ZOOM_BOX_COLOR |
| 14 | STROKE_COLOR |
| 15 | LOCK_COLOR |
| 16 | OUTPUT_BACKGROUND_COLOR |
| 17 | FREESTYLE1_COLOR |
| 18 | FREESTYLE2_COLOR |
| 19 | FREESTYLE3_COLOR |
| 20 | FREESTYLE4_COLOR |
| 21 | JUNCTION_COLOR |
| 22 | MESH_GRID_MAJOR_COLOR |
| 23 | MESH_GRID_MINOR_COLOR |
The actual color associated with the color index is defined on a per tool bases. Objects are typically assigned their corresponding color index, but it is permissible (sometimes) to assign other color index values to different object types.