here is what is available to the best of my knowledge. Greg is absolutely right that there is a hint of blue (perhaps purple?) in one of the black straps.
In each of the 3 colours: Dark Brown, Brown, and Black there are two shades (which in my opinion also corresponds with two skin patterns).

if memory serves me correctly, there have been a few forummers who have had on Santonis on their Portuguese Automatics, or the regular brown IWC alligator on the FA Jones - do check the archives. One example among others, is here: www.iwc.com/forum/en/discussion/31381/
The steel handwound FA Jones with the blue hands and the enamel-like dial appeals to me also - but for me, who is in need of a 'blue' watch, I would have gotten a blue strap for it -- but this is just me filling my 'blues' mood :)