It depends on the age of the silver, if it is more than 4 years old it will be dull.
oxydization
Grey, dull silver.
it tarnishes and can make a dull layer of metal oxide on the surface"tarnish" or oxidation.
because of high alkalinity and reactivity, these metals react with oxygen (or other gases) and form a dull layer over them. The inner part remaining protected against gases look shiny, but after sometime they also become dull.
Pure silver, gold, and platinum are very unreactive so they do not become dull.
It depends on the age of the silver, if it is more than 4 years old it will be dull.
oxydization
ornaments of silver look dull because silver reacts with h2s gas present in air to form black silver sulphide so it looses its shine
Grey, dull silver.
High purity must be shiny, but if oxidized it will become dull
dull grayish silver
Dark, Dull Grey
It's called oxidation. Rust if it were on steel. Oxygen in the air combines with the silver and causes it to darken.
Your hearing
It is in fact the best radiator. Dull black is the best absorber and emitter. Then shiny black, followed by white, then silver. While the best reflector goes the other way around (silver's the best, then white, followed by shiny black, then dull black)
Their dull coloring is for camouflage so they don't become a delicious and nutritious meal.