When you get right down to it, most the chemical elements have a ho-hum appearance. Silver. Gray. Silvery-White. Blue-Gray. Metals. Boring. Sulfur is different. The solid is bright yellow. If you melt sulfur, you get a blood-red liquid. If you set it on fire, you get a blue flame.
Sulfur is a common element. It's necessary for life, yet some of its compounds are toxic. For example. though you can metabolize a small amount of hydrogen sulfide, it doesn't take much to induce respiratory paralysis, which can lead to death. Though hydrogen sulfide has a distinctive rotten egg odor, the gas also deadens the sense of smell, so you can't gauge exposure using your nose.