I have tried a few multi-coloured pens but the Pilot Hi-Tec C Coleto is by far the best. It's convenience and ease of use is top-notch for me. It allows for users to customize their colors and carry all those colors in just one hand, ready in just a click! The Pilot Hi-Tec C Coleto definitely makes my stationery staples.
I love using this refill. It's handy and functional. The selection of colors are bright and happy, which adds a fun spice to your planner. The different sizes also make it easy to go from drawing, lining, and filling in spaces. All in one stroke! The inks dry easy and it doesn't bleed on my Hobonichi's Tomoe River Paper. You just have to wait for the ink to set in to avoid smear episodes. All in all, a good EDC