I said I'd get some better photos, so here's some from this evening (unfortunately not in good daylight, but at least taken with the camera on macro, as opposed to quick camera shots).
You can see that there is absolutely no pattern in the black stripes. Colour-wise, I'd described the dorsal stripe as being more grey than anything, in better light there is a yellow tinge to it. There's definitely no red, even between the scales.

Anyway, the photos (click to enlarge):











Hope you like Nobby, s/he's a good looking snake. Unfortunately the vent photos I tried weren't any better than the one I've already posted. I think we'll let Nobby grow a bit before we try with new photos.