Nuclear Plant Worker:
The red one is plutonium-239. 10,000,000th of a gram causes cancer. The yellow one in strontium-90. It gets inside you and causes leukemia. The purple one is cesium-137. It affects reproduction. It causes mutations. It makes monstrosities. Man's stupidity is unbelievable. Radioactivity was invisible, and because of its danger, they colored it. But that only lets you know which kind kills you.