function to randomly generate a color with a set opacity

generateRandomRGB.js

// default shade value of 200, increment up to 255 for brighter colors, deincrement down to 0 for darker colors

const generateRandomRGB = (shade = 200, alpha = 1) => {
  shade = (shade >= 0 && shade <= 255) ? shade : 255;

  const generateRandomColor = () => {
    return Math.ceil(Math.random() * shade);
  }

  const red = generateRandomColor(shade);
  const green = generateRandomColor(shade);
  const blue = generateRandomColor(shade);
  return `rgba(${red}, ${green}, ${blue}, ${alpha})`;
}