It's a bit sad when your day is saved by a moth. These are quite common in dark areas and they always look to be just brown - some dark bits but basically brown. @lyndemc would love them.
However, as this pic shows, under the flash, they actually have quite a bit of lilac in the wings also.
Seeing as how it turned out to be quite pretty, I thought that I couldn't just leave it as a moth so I asked the eminent Entomologist, Prof Google and he says it is a Speiredonia Spectans or a
Granny's Cloak Moth
You bet I'd find this beautiful! Just look at those patterns and designs all done up in browns. Those 'evil eyes' on the wings have a rather menacing look to them. Your capture really brings that out.