EnerGel is a water-based gel ball point pen that combines smooth writing, clear and crisp text, and smudge-resistant quick drying. Clear axis design to show ink color.. By seeing the refill pipe and identifying the ink color at a glance, you can intuitively access to paper without stress.. In addition to the classic black, blue, and red ink colors, we have also released blue black, turquoise, blue and orange ink colors for a casual expression of your personality.