How versatile is a black suit? As versatile as the owner wants it to be I would say! I must state from the outset that when it comes to suits, I have a strongly biased inclination towards shades of grey and blue. 
In all honesty I have never found a black suit the least bit exciting, well until recently that is. In all honesty I did not find the idea of a black suit that exciting until recently.
My lack of fascination with the idea of a black suit partly stems from its historically exaggerated importance as the ultimate mark of sophisticated male formal dress and by extension refinement. Do not get me wrong, I am not against conservative dressing, it has its place and occasion, but I am not convinced there is anything uniquely special about a black suit, which you cannot get from a navy blue or charcoal grey suit.
Having overlooked my solitary black suit for some time, I decided to pull it out of the wardrobe and give it some game time. Fabric is important but for me fit is king. With a properly fitted suit you can get away with a lot, even if said fitted suit happens to be black in hue.
As we get into winter the turtle neck is becoming increasingly significant, so I decided to throw it under my black suit for a bit of savoire-faire. Apart from the obvious functionality of the combination, I find there is a certain bravado to this look, a silent expression of confidence. Moreover, it goes perfectly well with a trench coat and a scarf in extremely cold weather.
You can make your presence felt in a boardroom without a power tie. Assert yourself without uttering a word by throwing a solid (preferably blue or black) golf shirt under your suit. For me this look represents a perfect balance between formal and adventurous, between caution and imagination.