1

public void comecaJogo1(int t)
{
        jButton1.setBackground( new Color( 255, 100, 100 ) ); //vermelho fraco
        try {
            Thread.sleep(100);                 //1000 milliseconds is one second.
        } catch(InterruptedException ex) {
            //Thread.currentThread().interrupt();
        }
            jButton1.setBackground( new Color( 255, 0, 0 ) ); // vermelho forte
}