I find VW too cumbersome to create renderings to present to a director as concept presentations, as well as you have to had made all your technical decisions (type of instruments, positions,etc) before you make your aesthetic decisions. I use VW for record rendering afterwords, when I have time.
What I do for presentation renderings is use Virtual Light Lab. It is a program that allows one to easily place instruments and colors to get a quick rendering of looks. I have found it really helpful, as you can show a director a look and if they don't like it, you can adjust the look right there and show other ideas. Granted it has limitations, but for fast and accurate color rendering of lighting, and working out aesthetic decisions, there is nothing like it.
The colors and color mixing are extemely accurate.
Jim