@celestion
Binaries are executables of programs which don't need to be built from source. They 'just work', or they don't. Like the .exe files in Windows.
Debian is a Binary distro, as are all Debian-derivatives (Ubuntu, Mint, etc). Gentoo Linux builds everything from source, which requires the steps to make the binaries which are then built specifically to your hardware, but this takes some time and effort.
Xflux is solely distributed as premade binaries.
The thread I linked to had to do with Nvidia drivers suddenly accounting for 11-bit screens and xflux being built only on 8-bit and 10-bit screens. They made the xflux11 binary to account for it, and also the xflux12 binary to further narrow down the issue, and I'm sure it's supposed to be rolled out properly to the various distros given the problem was solved by them.
Your problem seems to be related to the Voyager Mod gtk2 theme or the Thunar file manager not playing fair with one another and has no relation to your xflux install whatsoever.
If you open terminal and try to run /usr/bin/xflux (or /usr/bin/xflux11) and xflux gives you the error as shown in the linked thread, then it's worth to look at downloading the fixes which have been posted in there (xflux11/xflux12) and see if those work better on your system.
Otherwise you may need to contact the gtk2 theme maker or thunar devs for your specific issue.