Is this your entire code?
well to have a animation you need to have setup() and draw() - see the first text tutorials
E.g.: The section Hello mouse here: https://www.processing.org/tutorials/overview/
also, it helps to have background at the beginning of draw()
Also repeat bras2 = 305;
because it won’t go back to its initial value automatically
float bras2 = 305;
void setup() {
size(800, 800);
background(0);
}
void draw() {
background(0);
if (keyPressed == true ) {
bras2 = 255;
} else {
bras2 = 305;
}
fill(#E3DBC3);
rectMode(CENTER);
rect(365, bras2, 10, 80);
rectMode(CENTER);
rect(235, bras2, 10, 80);
}