Automated tools that skin a site allow people to choose the colors and see the effect without any technical knowledge or access. This is the perfect way for a web client to ‘design’ their own site. They have the time and ability to select the colors they like. Once they are satisfied, the site provider can ‘lock’ the colors. This saves a tremendous amount of time for the client and provider, as well as avoiding alot of friction.
The are obviously limitations to this approach, and clients and providers must be aware of them.