The EnerGel family of liquid gel pens offers a variety of choices from retractable to capped, fine point to bold, several barrel styles, and a wide selection of vibrant ink colors. With so many options, you're sure to find an EnerGel pen that matches your style. EnerGel RTX pens come with either black, red, blue, green, or violet ink. However, they can be refilled with any EnerGel refill available in a variety of other vibrant colors to match your mood and keep your writing instrument unique to you.