What color is the atom sulfur?

Answer 1

Atoms don't have colors per se, as they are much smaller than visible light waves.

Tin itself has two forms that are likely to be encountered at ordinary temperatures and pressures: the normal form at room temperature is "white tin" which looks sort of like aluminum, and at cooler temperatures (below about 50 degrees Fahrenheit) the "grey tin" form can occur; it's a sort of dull grey color and isn't really metallic (it's also crumbly, so things made of pure tin in cold climates don't tend to last long).

Answer 2

Individual atoms of sulfur don't have a color; they're too small.

Elemental sulfur can be any of a variety of colors. The most common one under normal conditions is yellow, but deep red and blue are also possible.