Plz run the code, it will be easier to explain that way.
I want red to be on the right sight, now it's on the left side.
How can i fix this?

(if it can be fixed multiple ways then i'm glad to know them).

1. void setup() {
     size(400, 400);
     colorMode(HSB, 360, 100, 100);
   }   
   
   void draw() {
     background(204);
     int H;
     translate(width/2, height/2);
     point(0,0);
     float a = atan2(mouseY-height/2, mouseX-width/2);
     rotate(a);
     translate(100, 0);
     H = int(map(a, -PI, PI, 0, 360));
     fill(H, 100, 100);
     rect(-12, -5, 24, 10);
   
   }