<canvas width="600" height="400"> </canvas>
<script>
var screen = document.querySelector ("canvas");
var brush = screen.getContext ("2d");
brush.fillStyle = "lightgray";
brush.fillRect(0, 0, 600, 400);
function drawCircle(x, y, radio, color) {
brush.fillStyle = color;
brush.beginPath();
brush.arc(x, y, radio, 0, 2*3.14);
brush.fill();
}
drawCircle (300,200,15,'red');
drawCircle (330,200,15,'black');
drawCircle (270,200,15,'orange');
drawCircle (300,170,15,'yellow')
drawCircle (300,230,15,'blue');
</script>
