The whole any-color pen thing started in 2014, when a gadget called the Scribble Ink pen hit Kickstarter.

The cartridge- or converter-filled pen comes in three colors: Lumiere, DC Battery Blue and AC High Voltage Green. Price: $169 Retro 51 Tornado Popper Bandit Popper Tornado Bandit packaging.

I’ve always dreamed of having a stunning display of rainbow gel pens in my stationery shop, and finally bringing that vision ...

This set comes with 10 gel pens in a range of bold colors, including black, green, and red. Each pen has a medium point that’s 0.7 millimeters in size. This pick is also available in three, four ...