Color scheme? Well, green goes with everything, right? We're plant nerds, so forgive our bias! If your color scheme is purple and pink, then your terrarium can have adorable purple waffle and polka-dot plants. All the colors of the rainbows can be expressed within a plant terrarium. But you can't go wrong with happy, green moss. Don't forget about succulents, with their muted tones and sculptural shapes.