Heya. Nice models
I like your scheme. A couple of suggestions if you dont mind. Maybe look into buying some washes, these whould add loads of depth to the models.
Also you might want to try some simple highlights. If you add a little white to your red and just highlight the edges of the models it will really make them pop.
Oh and when taking photos try placing your models on some white paper. It makes it easier for us to give you feedback
Keep up the good work.