The real rover has six driven wheels. For simplicity only the four corner wheels will be driven and the two middle wheels will rotate freely. The steering is accomplished using four servos, one at each corner wheel. The go to steering maneuver for this rover seems to be turn the four corner wheels in and rotate in place. All of these motors will need motor drivers. For this I chose the L298N motor controller modules requiring 4 digital output pins. One of them can drive two DC motors. Each stepper motor is driven by an A4988 stepper motor driver requiring 2 digital output pins. The directional input is via a joystick requiring 2 analog inputs. The total input/output count is 16 digital output pins and 2 analog input pins. A single Arduino Uno should work for this project.
The color of the 3D printed parts are chosen to be as accurate as possible. Some of the parts are printed using filament changes to produce more accurate looking parts and keep the assembly to a minimum. One example is the solar panel. The base of the panel is white with a single height copper layer followed by black solar panel modules. Most slicers should be able to perform this trick including Cura and the Prusa slicer I use.