Now with random seed.

src/main.rs

@@ -1,19 +1,23 @@
+extern crate rand;
 extern crate ansi_term;
 
 use std::io;
 use std::io::prelude::*;
 use std::f32::consts::PI;
 
+use rand::{thread_rng, Rng};
 use ansi_term::Colour::RGB;
 
 fn main() {
+    let r = thread_rng().gen_range(0, 256);
+
     let stdin = io::stdin();
 
     for (n, line) in stdin.lock().lines().enumerate() {
         let line = line.unwrap();
 
         for (o, c) in line.chars().enumerate() {
-            let (red, green, blue) = rainbow(0.1, n + o);
+            let (red, green, blue) = rainbow(0.1, r + n + o);
 
             print!("{}", RGB(red, green, blue).paint(c.to_string()));
         }