JSFiddle - React, Tailwind, and code Playground

JavaScript

var i = 0;
var b0t = 100;
var b1t = 3.5 * b0t;
var wl = 100;

function pulses (){
    bytes = "1001101010110101001000100";

        bit = bytes[i];

        i += 1;

        document.body.style.backgroundColor = 'white';
        document.body.style.color = 'white';
        
        setTimeout(toblack, wl);
        
        if(i <= bytes.length) {
            if (bit == 1)
                setTimeout(pulses, b1t + wl);
            else
                setTimeout(pulses, b0t + wl);
        }
}

function toblack() {
    document.body.style.backgroundColor = 'black';
    document.body.style.color = 'black';
}

pulses ();