What it is supposed to do is mitigate shadow strength and reduce the chroma of the ambient light but i never could control it properly. Seems irrelevant in LightWorks. However, OpenGL renderings can have interesting tints when you play with sun and ambient colors. Haha.
I just misspelled "sun" as "sin."
"Sin color."
Everyone knows sin is scarlet-colored.
Dwight Atkinson