It was bright and fast, being about +1 or even a bit brighter, and flaring briefly to -1 at about 19:34:43 UTC. It was distinctly orange in colour.
I captured it on photograph together with a bright stray, the Kosmos 1346 rocket (82-027B). It was all a lucky shot, as clouds were moving in fast (and can already be seen at the top of the image)
The detail image below, shows the distinct orange colour of the HTV-1. It is due to the spacecraft being wrapped in protective orange-coloured metal foil.