I like that the video shows a variety of uncommon animals exemplifying camouflage that kids may not typically see or think of. The activity has a clear objective from an adult perspective, but some extra guidance may be useful for younger students who may look at this as a coloring exercise and miss the intention behind it. If I were preparing this activity for a group of young students, I would let students pick a habitat based on three predetermined coloring pages that I either pulled from the web or drew with a sharpie myself. I would then instruct students to color three different animals that I again either acquired or drew myself. Once they have colored and cut out all three animals, I would have them place all three animals in their new environment to see which ones blend in best. If you really like the idea of students drawing their own environments, or doing three separate ones, then perhaps give them three different colored pieces of construction paper to draw them on to help them out, like a green paper for a forest, field, or bog, tan for a desert or African savanna, white for snow, etc. Kids have a tendency to get lost in coloring and their attention span might be wiped out for a discussion on the topic after coloring, I suggest outlining the figures or give them coloring baselines to help nudge them towards a positive outcome.