Can Someone Tell Me If These Coins Are Silver?

Silver tarnishes. Thus out went the silver silver wear as it need to be polished. Thus coin are also affected by their surroundings. Sulfur tends to turn coin yellow in color. (even if is in the air) Looks like the dime is showing tarnish, but the gray you can see brown and gray. Note sure what causes the gray? Albums/paper/envelops/fingerprints/sneeze droplets, acid and other things will affect coins. Something are desirable, others makes you want it gone. But best to not alter color because if the coin is graded and they deem it altered, then it will perhaps be dropped a couple or grades, or just listed a 'genuine' with no grade. (especially on silver coins) If a silver coin is dipped in acid, it removes the out layer of the coin. With that layer gone, it looses grade as well. Soon the coin is no longer shiny. So best not to alter a coin. The coins future will pay for it.

Just leave them as they are. They are just showing their age and some wear.

Personally, I kind of like a coin that's been circulated, like yours.

[ai] with the above. Silver, but worth spot

No.
Silver War Nickels are 40% Silver while the pre-1965 dimes, quarters, halve dollars, and dollars are all 90% Silver.

Worth melt value, but still, that's considerably more than face so in my book that's worth holding on to.