- Copy the blueforest.xml into the Styles-Directory of your Qt Creator installation.
- Select the theme within
Tools > Options > Text Editor > Color Scheme
You can install the theme using the following command on a Terminal:
cd ~/.config/QtProject/qtcreator && test -d "styles" || mkdir "styles" && cd "styles" && wget https://raw.githubusercontent.com/lichtzeichner/blueforest-theme/master/qtcreator/blueforest.xml
The path for installing on windows is (create the styles folder, if it doesn't exist):
%AppData%\QtProject\qtcreator\styles
Download the blueforest.xml file and place it in that directory.