Flat themes for Houdini, to be easier on the eye.
Dark:
Light:
Modo Style, inspired by the Modini theme posted on the SideFX forums. To get the viewport in the right style, use the 3DSceneColors.bw file taken from the Modini theme and set your viewport background color to grey.
Copy the *.inc and *.hcs files to the config subfolder (you can just create it if it's not there yet) in your Houdini user folder (typically $HOME/houdini19.5 or similar).
To get a modo-style (darker) grey background, add the *.bw file as well. This can then be used by going to the display options in the Viewport and chosing the Grey background.
Copy the files to install, then go to Edit > Color Settings and choose the new theme from the dropdown.
These themes are very usable, but probably an ongoing work in progress.
Some cleanup would be needed, as the themes probably contain a lot of uneeded lines. Also, additional comments to aid in identifying which UI element corresponds to what are needed.