Background(128);
NoStroke();
Fill(255, 0, 0, 255);
// without alpha value
// Fill(255, 0, 0);
Circle(100, 100, 50);
Background(228);
NoStroke();
double red = Random(0, 255);
double green = Random(0, 255);
double blue = Random(0, 255);
double alpha = Random(0, 255);
Fill(red, green, blue, alpha);
Circle(100, 100, 50);
Background(128);
NoStroke();
Timer = Draw;
void Draw()
{
double red = Random(0, 255);
double green = Random(0, 255);
double blue = Random(0, 255);
double alpha = Random(0, 255);
Fill(red, green, blue, alpha);
Circle(MouseX, MouseY, 50);
}