var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");

let selection = [];

color.onchange = () => {
  selection.forEach((c) => (c.color = color.value));
};

c.onmousemove = ({ clientX, clientY, buttons }) => {
  if (buttons > 0) {
    ctx.fillStyle = color.value;
    ctx.beginPath();
    ctx.arc(clientX, clientY, size.value, 0, Math.PI * 2);
    ctx.closePath();
    ctx.fill();
  }
};