It's important to know whether your coloring materials are lightfast or not. We selected oil paints and acrylic paints that have been thoroughly tested and are proven to be permanent colors that are durable over time. The better brands of oil and acrylic paints have ASTM ratings for lightfastness. ASTM stands for American Society for Testing and Materials.
Lipcolor pencils don't come with that information. Neither do stencil paints, RIT dye and nail polish. Partly because they don't have to... many of the materials we use on vinyl were intended for other purposes than art projects. Whether the color will hold up for 100 years isn't even an issue with the manufacturer.
I haven't seen colorfast ratings for the Genesis Paints. I have not seen any ASTM information on the Delta or Plaid craft paint products either. The craft paints are very popular but the companies provides little or no information on the quality of their products. This doesn't mean we shouldn't use these products but it's something to be aware of.