function generateRandomColorStyle() {
  const colorR = Math.round(Math.random() * 255);
  const colorG = Math.round(Math.random() * 255);
  const colorB = Math.round(Math.random() * 255);
  return `rgb(${colorR},${colorG},${colorB})`;
}
Generate a random color style for canvas strokes and fills.

@returns {string} Style string in the form of 'rgb(100,200,250)'.