Probably the .22 Colt Centennial Commorative, a scaled-down M1860.
They are not cap and ball revolvers, just look like it.
They are .22 single shots and will have to be yellow sheeted.
Colt also marketed .22 Short single shot derringers, two in a fancy box, each slightly different in color, as were the "C&B" revolvers.
They are all a POS and shouldn't be fired.
Most missfire and all have pot metal frames and barrels with steel liners in them.
They show up from time to time, people buy them at estate sales and think they struck gold, but they didn't.
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