Macro tag 

macro_rules! tag {
    (@open, $arg:expr) => { ... };
    (@open, $arg:expr, @color=auto) => { ... };
    (@open, $arg:expr, @color=fore) => { ... };
    (@open, $arg:expr, @color=$color:expr) => { ... };
    (@open, $arg:expr, $color:expr) => { ... };
    (@open, $arg:expr, $color:expr, @color=auto) => { ... };
    (@open, $arg:expr, $color:expr, @color=fore) => { ... };
    (@open, $arg:expr, $color:expr, @color=$fore:expr) => { ... };
    (@close, $arg:expr) => { ... };
    (@close, $arg:expr, @color=auto) => { ... };
    (@close, $arg:expr, @color=fore) => { ... };
    (@close, $arg:expr, @color=$color:expr) => { ... };
    (@close, $arg:expr, $color:expr) => { ... };
    (@close, $arg:expr, $color:expr, @color=auto) => { ... };
    (@close, $arg:expr, $color:expr, @color=fore) => { ... };
    (@close, $arg:expr, $color:expr, @color=$fore:expr) => { ... };
    (@wrap, $tag:expr, $arg:expr) => { ... };
    (@wrap, $tag:expr, $arg:expr, @color=auto) => { ... };
    (@wrap, $tag:expr, $arg:expr, @color=fore) => { ... };
    (@wrap, $tag:expr, $arg:expr, @color=$color:expr) => { ... };
    (@wrap, $tag:expr, $arg:expr, $color:expr) => { ... };
    (@wrap, $tag:expr, $arg:expr, $color:expr, @color=auto) => { ... };
    (@wrap, $tag:expr, $arg:expr, $color:expr, @color=fore) => { ... };
    (@wrap, $tag:expr, $arg:expr, $color:expr, @color=$fore:expr) => { ... };
    ($arg:expr) => { ... };
    ($arg:expr, $color:expr) => { ... };
    ($arg:expr, @color=auto) => { ... };
    ($arg:expr, @color=fore) => { ... };
    ($arg:expr, @color=$fore:expr) => { ... };
    ($arg:expr, $color:expr, @color=$fore:expr) => { ... };
}

colorfully wraps the given text in “<”, “>”: “<{text}>”