Since you are posting on a forum which uses lime plaster, I should point out there is an art form, now lost, where you hand model a type of lime plaster into a bas relief. The driving force was decorative and was common throughout Europe, Asia and the Middle East. In Europe this was called 'stucco' before this word got switched to its modern usage. The stuccotares were in higher demand than painters, because the end product looked like expensive carved stone and could be done in place.

You could practise with hydrostone or drystone plaster (the hardest plasters) but you have to 'retard' the cure. Ask you local plaster/gypsum dealers for these items. The plaster is too fast otherwise.

The plaster and lime can take color but what looks nice is a light coat of red shellac and then use a paste wax tinted white - wait for it to dry then hand buff it to a light shine.