This was a big thing for me because I use windows in INVERTED COLOUR mode so all the icons look wrong. To correct it I edited the icons.py to invert all embedded images.
You need Python install and download source code version of TaskCoach and replace the file e.g.
C:\Program Files (x86)\TaskCoach-1.4.3\taskcoachlib\gui\icons.py
This was a big thing for me because I use windows in INVERTED COLOUR mode so all the icons look wrong. To correct it I edited the icons.py to invert all embedded images.
You need Python install and download source code version of TaskCoach and replace the file e.g.
C:\Program Files (x86)\TaskCoach-1.4.3\taskcoachlib\gui\icons.py
With the file here:
https://drive.google.com/open?id=0Bw4RtQYx8BukSkU0VzhsQXFoMXc
All the images/icons in TaskCoach are Base64 encoded, rather than separate file, which makes editing and adding images tricky to say the least!