extern crate termion; use termion::color::{DetectColors, AnsiValue, Bg}; use termion::raw::IntoRawMode; use std::io::stdout; fn main() { let count; { let mut term = stdout().into_raw_mode().unwrap(); count = term.available_colors().unwrap(); } println!("This terminal supports {} colors.", count); for i in 0..count { print!("{} {}", Bg(AnsiValue(i as u8)), Bg(AnsiValue(0))); } println!(); }