void setup() {
size(600,600);
background(160,210,230);
}

void draw() {
stroke(0);
fill(random(0,255), random(0,255), random(0,255));
rect(mouseX, mouseY, 50, 50);

if (mouseX > 300) {
}else fill(0,0,255);
rect(mouseX, mouseY, 50, 50);

if (mousePressed) {
background(250);
fill(0);
rect(mouseX, mouseY,50,50);

if (mouseX < 300) {
}else fill(0,255,0);
rect(mouseX, mouseY, 50, 50);

for(int lineX = 10; lineX <= 300; lineX += 10){
line(lineX, 0, lineX, height);

}}}