To get true realistic color ramping is difficult with traditional 3D printers; you can go powder/composite route but the colors tend to be a little muted/toned down and the items are still extremely fragile even after dipping and treating with Cyanoacrylates/Superglue… using DLP resin prints would produce very nice models but no color and you would have to prime/paint each model accordingly or look into some testing with high quality hydrographic films to get the color transferred to your model.
Depending on the forms and undercuts you might look into the new color/paper 3D printer Mcor ARKe.
You can get full color ramping and once the element is treated it’s essentially a solid block of paper/wood.
