Temporal dithering

dither.js

var swatch = document.createElement('div');
swatch.style.width = 500;
swatch.style.height = 500;
document.body.appendChild(swatch);

function turnRed() {
    swatch.style.backgroundColor = 'red';
    requestAnimationFrame(turnBlue);
}

function turnBlue() {
    swatch.style.backgroundColor = 'blue';
    requestAnimationFrame(turnRed);
}

requestAnimationFrame(turnRed);