click ellipse once it turns from blue to red; how can i make it so another click makes it go back to blue again? (sorry, insert code function not working...)

 

Button buttons;
Button buttons1;

void setup() {
  size(500, 500);
  smooth();
  buttons= new Button(50, 100, random (20, 80), color(0, 0, 255));
  buttons1= new Button(80, 180, random (20, 80), color(0, 0, 255));
}
void draw() {
  buttons.display();
  buttons1.display();
  buttons.rollOver();
  buttons1.rollOver();
}

class Button {
  float x;
  float y;
  float radius;
  color c;
  boolean click=false;

  Button(float _x, float _y, float _radius, color _c) {
    x=_x;
    y=_y;
    radius=_radius;
    c=_c;
  }

  void display() {
    if (click) {
      fill (255, 0, 0);
    }
    else {
      fill(c);
    }
    ellipse (x, y, radius, radius);
  }

  void rollOver() {
    if (sqrt(sq(mouseX-x)+sq(mouseY-y))<=radius&&mousePressed ) {
      click=true;
    }
  }
}