Since coloring pages can vary greatly in intricacy and design -- those for younger children can be simple while those for older kids can be much more detailed and intricate -- it's worth doing a little research to find the best free coloring pages for older kids. Here are some great sources for advanced coloring pages for older kids.

1. Kids Printables Coloring Pages
This amazing collection of free coloring pages is perfect for older kids.

There are thousands of detailed pictures of every subject imaginable, from flowers, plants, and wildlife to favorite cartoon and movie characters such as those from Star Wars, Harry Potter, Toy Story and much more. The intricate details and beautiful illustrations are sure to captivate older kids, and you’ll also be able to find some coloring pages that’ll interest younger siblings, such as those with Dora the Explorer and Bob the Builder themes.

2. Edupics
This site has more than 10,000 free printable coloring pages, sorted by categories as wide ranging as school, food, holidays, and more. There are lots of great coloring pages for younger children, but you’ll also find a great variety of more complex pictures that will be more challenging for older kids.

3. Free Printable Coloring Pages
The best part about this site is that it offers free coloring pages for both older kids and younger siblings. So while there are lots of simple pictures of, say, snakes and frogs, you’ll also find detailed coloring pages of reptiles that will appeal to older kids.

Some butterfly pictures will be easy to color while others will feature many more intricate details that will be more challenging for older kids.

4. Coloring-Kids.com
This site is chock full of great free coloring pages for older kids featuring everything from superheroes to transportation to countless other subjects and themes. One of the best groups of coloring pages for older kids is the numbers category, which features multiplication coloring pages. Kids have to color in the pictures using a paint-by-numbers formula, but they first have to figure out the multiples of each equation before they can figure out what that number is. Fun, and a great tool for encouraging older kids to learn their multiplication facts while they color.

5. Mandala Coloring Pages
Mandalas, which are intricately-patterned circles, may have spiritual and ritual meanings in Eastern religions and philosophies; but to kids, they can be a fun piece of art to color.

The detailed and complicated patterns may be too difficult for younger children, but they are perfect for older grade-school age kids. And the benefits of coloring mandalas may go beyond fun. In fact, mandala coloring books are now used in meditation and art therapy, and people often report a sense of calm and well-being when coloring mandalas.

So the next time you’re looking for fun coloring pages for your older kids, try some free mandala coloring pages.

6. Crayola Coloring Pages
Crayola has some really great printable coloring pages for older kids. There are illustrations of the human body (the eye, the heart, the skeleton) as well as coloring pages that are also games and puzzles. Challenging, educational, and fun!

7. USA-Printables.com
Here’s a great site for education coloring pages for older kids. Built around the theme of U.S. history, the site offers lots of lessons about historical people, places, and events. From the Boston Tea Party to Mount Rushmore, you’ll find coloring pages depicting great moments and figures in American history.

8. DLTK's free coloring pages site
There's something here for grade-schoolers both young and older, from alphabet and animal coloring pages to famous works of art such as Edvard Munch's "The Scream."

9. The University of Texas at El Paso Learning Links Coloring Pages
This site offers coloring pages as well as information about different animals, cultural artifacts, and more. Your child can color a black mesa pitcher, a Navajo cradleboard, and a burrowing owl, among other educational objects and creatures.