Alex wrote:So currently I've decided to just add this hidden option, so one can just force colored icon in case the monochrome one does not suit his config.

Currently desktop Linux distributions use desktop environments with full-colored icons as default and there is no real reason to configure FDM for use on some specially crafted router Linux distros. Maybe you should properly configure your Linux virtual machine? If you think about compatibility, you should better compile 32-bit FDM for Windows XP.

What is more, FDM now supports dark and standard desktop themes, so icons may be selected according to this setting.
It means that FDM should use full-colored icon by default as light theme is default for FDM. Monochrome icon should be used only when FDM switches to dark theme. I think it would be the best solution for most users.