<canvas width="600" height="400"></canvas>
<script>
var tela = document.querySelector("canvas");
var pincel = tela.getContext("2d");
pincel.fillStyle ="lightgray";
pincel.fillRect (0,0,600,400);
function chamaCores(x,y,raio,cor){
pincel.fillStyle = cor;
pincel.beginPath()
pincel.arc (x,y, raio, 0,2*3.14);
pincel.fill();
}
chamaCores (300,200, 10, "red");
chamaCores (300,180,10, "black");
chamaCores (280,200,10, "yellow");
chamaCores (320,200,10, "blue");
chamaCores (300,220,10, "orange");
</script>
