Brandhasitgoing, If your ball are swelling at all, you need to see a doctor. Blue balls is an uncomfortable feeling, not a physical condition due to the blood that caused the erection not completely leaving your genitals. It normally will happen because of many cycles of arousal and resolution without reaching orgasm. Your testicles should not sell up. 'Blue balls' are just a term for it. It does not have anything to do with your balls or the color blue.
BTW, 'blue balls' are easilly 'cured' by masturbation.