Adult coloring books have taken the world by storm, with people picking up their crayons from childhood and reliving some of their best years.

That's because coloring is not just for kids. Not only have professionals discovered that coloring is good for one's mental health, but it's also just plain fun — and let's face it, the world can always use some relaxing fun.

However, there's so much more to adult coloring books than pretty swirly lines and colorful (pun intended) swear words. There is also a whole market of adult coloring books just for geeks. That includes color-your-own comics to coloring books based on some of the hottest geek franchises. Here are some of the best geeky coloring books for those who just want to sit in a quiet corner of the world and color in the lines.

Harry Potter Magical Creatures

Coloring is magical, but add some creatures from Harry Potter and the right colored markers, and it's downright fantastical. From house elves to merpeople, this coloring book features those magnificent beasts from the Harry Potter movies. The book also features concept art and stills from the films.

Art of Coloring Star Wars

Coloring isn't just art, it's art therapy, or so says the cover of this Star Wars coloring book. Find the zen of Yoda by coloring these pages that feature pen-and-ink illustrations of landscapes and characters from the Star Wars universe. The book's packaging includes a board cover, along with metallic foil stamping.

Star Trek: The Next Generation Coloring Book

Join Captain Picard and the crew of the Enterprise as they travel through space to continue a mission to explore the cosmos and seek out new life and new civilizations. This book features 45 pages of coloring joy that will take Star Trek fans out into space to where no one has gone before.

Doctor Who Coloring Book

It's wibbly-wobbly time-wimey coloring fun in this book. Zone out and color a variety of settings, planets, aliens, Doctors and companions from the BBC series. Just don't forget that the TARDIS is always blue.

The Official A Game of Thrones Coloring Book

Make sure that red crayon is handy, because this is one coloring book that features a lot of blood. It's based on the hit series on HBO, and fans can fill in scenes from the vibrant, but often dark, worlds of Westeros and beyond.

ⓒ 2021 All rights reserved. Do not reproduce without permission.