Answer: Without knowing if this is a woody plant, house plant, or garden perennial it is a bit difficult to make a guess, but if sold as a house plant I think it might be a variegated form of Peperomia. The following page has a number of photos to show the wide variety this plant can show.
It might also be a succulent of some kind such as Sedum spurium "Tricolor". There are many different small succulents sold for the garden as well as for dish gardens.
I hope it is one of these. If not, you might try asking at the store where you purchased it, or see if your local reference librarian can help you find a photo of it in a reference source so you could identify it that way.
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