I try to make a circle gradient with two colors. I have the following code and of course don’t work. 

1. void setup(){
3.   size(200, 200);
4.   smooth();
5.   noStroke();
6.   //background(0);
7.   ellipseMode(CENTER);
8.   ellipse(width/2, height/2 ,180, 180);
9. }
10. 
    
11. void draw(){
12.   for (int i = 0; i < 255; i++) {
13.     fill(i);
14.     //ellipse();
15.     noStroke();
16. }

Any idea what to do;

I try to make a simple "image", I want an array with 255 columns and 1 line for every color from 0 to 255.