Make your coloring book pages pop by using markers to color it in! Similar to using paint, you'll want to make sure to remove the coloring book page, or at the very least insert a rigid, thick board behind the page in question so that the ink doesn't bleed. You can be straightforward with your marker coloring, or you can use it as an opportunity to transform your page into a work of pop art by filling in areas with boldly colored patterns.
There are many types of paints and plenty to choose from when tinting your embroidery. Watercolor paint is soft and beautiful. The color usually bleeds, so if you want a crisp line, create a stencil with freezer paper. The watercolor also makes a great background, rather than a fill, and can be used for landscapes, starscapes or more.