The orange flowers are lined along the entire branch and because of its unique structure, they are often called Chinese Hat Plant. Frequent heading back will result in a plant that seldom flowers, hence it is best to allow it to grow and branch freely and any pruning should only be done to encourage branching.
I saw the striking red flower variety at Nong Nooch Botanical Garden's Butterfly Hill though I still could not manage to get hold of any of it for propagation. Apparently there is also a yellow flower variety though I have not seen it myself.