Function gen_colors 

pub fn gen_colors(
    file: &Path,
    c: &Config,
    dynamic_th: bool,
    cache_path: &Path,
    no_cache: bool,
    quiet: bool,
    overwrite_cache: bool,
) -> Result<Colors>

How crate::colors::Colors is filled, returns the colors itself and a bool that indicates whether backends had some warnings or not (ugly workaround ik)