Tachyon will take standard X-Windows command-line arguments. Format can be specified by -format [type] on the command line, or as a resource.
These resources can be specified in an XTach file in the user's resource directory, as defined by the XAPPLRESDIR environment variable. A sample XTach file is usually supplied with distribution.
| Resource | Default | Description |
| | | |
| *foreground: | grey | Default foreground color |
| *background: | DeepSkyBlue4 | Default background color |
| *NodeFGColor: | yellow | Node foreground color |
| *NodeBGColor: | DeepSkyBlue4 | Node background color |
| *NodeHLColor: | cyan | Node highlight (foreground) color |
| *NodeBorderColor: | limegreen | Node border color |
| *NodeHLBorderColor: | peach | Node highlight border & text color |
| *EdgeFGColor: | yellow | Edge foreground color |
| *EdgeBGColor: | DeepSkyBlue4 | Edge background color |
| *EdgeHLColor: | cyan | Edge highlight color |
| *NodeChangeColor: | red3 | Highlight color showing changes in last network solve. |
| *UseIntensityToHighlight: | 0.4 | highlight using intensity (0.0 - 1.0) |
The resource UseIntensityToHighlight takes a floating point value between 0.0 and 1.0. If the value is 0.0, Tachyon will use the highlight colors specified in the resource file for highlighting. If the value is greater than 0.0, this will be used as a percentage of intensity increase that should be applied to the colors for highlighting.
| Resource | Default | Description |
| | | |
| *font: | *helvetica-medium-r-normal--12* | Font for labels |
| *formatfont#: | (as *font) | Font for format # (replace # with number) |
| *StringEditor*font: | *helvetica-bold-r-normal--10* | Font for inputs |
| *StringBrowser*font: | *7x14* | Browser font |
| *TimeLineFont*font: | *7x14* | TimeLine Tool font |
| Resource | Default | Description |
| | | |
| *format: | 0 | Seconds (or n-units) |
| *expert: | false | Expert mode (confirmations disabled) |
| *DataDirectory: | . | Directory with data (*.net) files |
| *NodeWidth: | 75 | Distance (pixels) from center to side edges |
| *NodeHeight: | 20 | Distance (pixels) from center to top/bottom edges |
| *Cursor*foreground: | white | Cursor color |
| *defaultConstraint: | unconstrained | Constraint placed on created edges |
| *showEdgeLabels: | false | Display labels on edges by default? |
| *layoutOrientation: | horizontal | Orientation of graph layout |
Note that Expert Mode assumes the user is completely confident in decisions they make. For example, under Expert Mode, you can exit Tachyon without saving changes to a modified graph and Tachyon will not warn you.