While assigned metamerism is not possible with LightWorks, the poster might have success using a facade assembly that includes a screen with tiny tilted bands. As the sun gets lower in the sky, the underside of the shaded bands will brighten to provide the change effect. A scrim....
Besides, what's the problem with just changing the material to suit the design vision at any given time of the day?
If this is for an automated sun study, I believe it possible to script material changes (GDL gurus please clarify) during the generation of the fly-thru.
Dwight Atkinson