Simple fix for Firefox for dark Linux themes. The problem was poor visibility of text in inputs and textareas.
Clone this repository.
$ git clone https://github.com/qwercik/FirefoxDarkThemeFix.git
Now change your directory
$ cd FirefoxDarkThemeFix
Then grant execution permissions to the firefox-fix.py.
$ chmod +x firefox-fix.py
Eventually run firefox-fix.py
$ ./firefox-fix.py
The code work correctly with default installation of Firefox 53 on Linux Mint 18.1 Cinnamon and Manjaro 17.0.1. The author is not sure that the patch will work correctly on other distributions and older Firefox versions.