I am using Geany 1.27 on Linux Mint 18 Sarah.
I have a dark theme installed everywhere due to eyestrain. In Geany I can choose my darcula theme in View > Change Color Scheme ... Unfortunately I have to choose that again every time I run Geany.
I have looked in preferences but cannot see a default setting. I have looked in the Geany install directory, but cannot see a default.conf to replace.