Well, apparently they were back then and still are today for people of all ages. People are making the adult coloring books bestsellers on Amazon! At the time of this writing, eight of the top twenty books on the bestsellers list, are coloring books for adults. There must be something behind this recent growth in interest.
If you really want to get right down to it, adults love to color as much are their kids do. If you dont believe us, think about all of the artists that do oil and watercolor paintings, those that do pen and ink drawings and watercolor pencil drawings and artwork. This is simply the more appropriate and acceptable way for adults to continue coloring as we all did as kids. This is partially why both adults and children alike really enjoy having SpongeBob printable coloring pages available to them to color on.
Some websites offer very basic coloring pages for kids that can be printed off and colored. Others create interactive coloring pages that require children to work on the computer itself to color the images. Unlike the basic websites, the interactive coloring pages are often found on more complex websites that act as a full-fledged community. The coloring pages are only one of many things available to do on a particular site.