What size are you looking for and how many plants do you want to place there? Will they be on the ground or on a shelf?

first thought was perhaps an evergreen shrub like Euyonimus . they come in green and silver and green and 'gold'. hardy slowish growing. but as loosestrife says what size of pot.
you could under-plant it with miniature bulbs for the soring and then some trailing bedding for summer.
welcome to GoY too :o)

Hi, welcome to GoY, Aucuba japonica looks good in a pot, and looks the same all year, have a look at A japonica 'Crotonifolia' Derek.