

These are labels sold by Que Intersante on Etsy meant to cover up your child's simple crayon color names like "Orangutan Orange" with hot new flashy names like "Mercuric Oxide". This is a pretty awesome way to get your children familiar with colors associated with things like chemical flames, dyes, and glowing gases as well as becoming comfortable with chemical nomenclature; if they can pronounce them that is. This is actually quite reminiscent of my childhood, when we didn't have crayons but had to grind up chemicals with our teeth and mix them with water so we could dip our quill pens and draw on some parchment...
"Hey Mom, I can't find my benzoylmethylecgonine white crayon anywhere; did you take it to draw on your nose again?"

Source...
Que Intersante on Etsy via Buzzfeed