Often times clients request standard day lighting to be sure that the colors are represented correctly. These renderings are generally used for their own color selection or city approval.
When the renderings are used for marketing purposes, in print or on a website, clients often prefer the sunset or dusk renderings because they have a more interesting, emotional feel. A large percentage of a purchase decision is based on emotion, so this look help to create that. I also think they are just more interesting to look at.
