How do I tint at 2D shape?

I tried tinting with tint(); but that only works with images, what should I do?

Do you mean just the color, not an image?

let fade_index = 255;

function setup() {
  createCanvas(400, 400);

function draw() {
  fill(255, 0, 0, fade_index);
  circle(width/2, height/2, 100);
  if(fade_index == 0) fade_index = 255;

[quote=“noel, post:2, topic:25727”]
fill(255, 0, 0, fade_index);
Thank you so much, I’ve been sitting at this problem for some time. On the p5 website it doesn’t explain what alpha changes, I should have tried. I’m still new to this <3