I made a small canvas wall hanging for my niece's room. The image is of a cartoon character on Nick Jr. I printed a coloring page off their craft/activity tab of their website and traced it onto the canvas and painted it. I've showed it to a few people who now want to buy one but I'm not sure if this is possible? If I am sticking to these coloring pages and just painting them without alteration, is that still copyright infringement? A few people have told me that using materials available to the public poses a grey area. For example, I see many people using the iron-on transfers from the website and selling t-shirts. I'm just not sure what's allowed.