Building a theme in bitweaver is no different to any other site styling. If anything it's easier since it defines a clear set of rules that need to be complied with, and taking a existing style may just be a matter of updating the site images and colours.

Style

One area which may or may not be appropriate is the ability to select a new layout style while using the same theme. On paper this is a good idea, but it is not really as necessary as was thought many years ago when it was designed. The original idea was that users who prefer menues on the right rather than the left could select that themselves, and for simple themes this works well, but more often, a single style is prefered by the sites owners in which case the style option is switched off.