Steps:

• Install Font "Roboto Mono" from https://github.com/google/fonts/raw/master/apache/robotomono/RobotoMono-Regular.ttf
• Open Regedit , File->Import-> "show all file types" then Select your theme file "DarkFox-Vfp9-Editor-Theme.txt"
• Restart Vfp or use SYS(3056) from the command window to reload registry settings.

Note:

• If you want to go back to default vfp values: go to /Main Menu/Tools/Options/Editor-> "Reset All" & "set as default"
• If you have a current color set different from default, you can save it before making changes: open Regedit and go to HKEY_CURRENT_USER\Software\Microsoft\VisualFoxPro\9.0\Options right click -> "export". Then just open the resulting .reg file to set back your values.