Thonny dark theme that provides higher contrast between the code and the background than the 'Default Dark *' themes.
Install Thonny, then use a shell:
git clone https://github.com/flinti/thonny-syntax-dark-high-contrast
pip install thonny-syntax-dark-high-contrast/
Open Thonny, goto Tools -> Theme & Font and select Dark High Contrast from the Syntax theme dropdown menu.
pip uninstall thonny-syntax-dark-high-contrast-flinti