While coloring pages may seem simple in the minds of parents and other adults these days, they are often the passport into a more creative style of play. Yes, your child will simply color the picture online, but by doing so, she is learning not only to stay inside the lines, but to balance color and texture and to simply use her imagination. If a coloring page for kids is the first step into a full-fledged imagination based entertainment package, it is unlikely many parents will find them simple for long.
This will help them to not only recognize different colors but to also learn the names of the different colors. Developing these skills will help in later development too as your child begins to learn to read and write. He or she can then learn how to write the names of all of the different colors. You see learning is progressive and incremental - it happens in stages. Step-by-step as I have described. This is the true beauty of learning...the more that your child puts in, the more they will get out of learning. As their knowledge grows, so will their interest in a range of different subjects.
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.