Macro construct_theme 

macro_rules! construct_theme {
    ($kw:expr, $hd:expr, $dsc:expr, $err:expr, $othr:expr) => { ... };
}

This macro eases the work of creating a new theme, instead of creating the theme struct yourself, you can use the macro to do so. The macro receives all the desired colors. Do note that the order in which you place your colors is important.

1. Keywords color
2. Headlines color
3. Descriptions color
4. Errors color
5. Others’ color