In this tutorial I’ll show you how to make the see-through colored X-ray look you would find in an airport x ray machine. You’ll learn how to dial in the opacity and dirt shader. Hope you find it useful!
Oh, side note, this is not realistic at all. If you want it to look truly accurate, here are some notes I found: Organic materials like paper, food and explosives are orange, while blue or green are used for metals and glass. The denser the material, the darker the color.