I have just been given some models of spears and shields that the Masai will hold. I was initially going to apply a black solid colour to the weapons; but it was suggested to me (I can't remember who by) that I experiment with different levels of shade.
Instead of a Solid Colour shader, I applied a toon shader called a Light Angle Two Tone. This meant that the level of colour that was present in the scene would be dependent on how much light is in the scene.
To test this, I key framed the directional light at frame 25 and I then rotated the light in the opposite direction.
At first the light was rotating in a vertical movement, which did not look like a sunset movement, so I simply added an inbetween keyframe at frame 13 to make the directional light rotate in a more horizontal movement, creating the illusion of a sun setting.