Don't know about you but I am constantly fidgeting with something at my desk... I love these. I use it both as a fidget when I'm not using the pen and take the lid off and continue to use it when I am using the pen. Awesome for pen clickers!
SO even when the ink runs out, highly recommend keeping, at the very least, the pen lip fidget section to use as a pocket or desk fidget.
This gel .5mm pen has black ink. Comes with a nib on the pen. You need to remove this for first use.