I like Midnight Commander (aka MC), its a freekin GREAT file manager, super easy to use and very powerful.
I have had an attempt to theme MC, taking inspiration from Breeze and the Nordic Green colour themes in KDE
It looks like this
This is the theme/skin I have spent the most time on, I'm pretty happy with it.
The config/ini file is available here
If you like this MC Skin simply copy the text here and save as an .ini file and place it in ~/.local/share/mc/skins/ then select the theme from within MC's appearance menu