For lighting, I used a large softbox camera right, a large white reflector camera left, and a flash directly onto the white background to blow that out completely.
The camera (Canon 20D) and lens (24-70mm) was on a tripod and I used a remote trigger to take the shot.
Many thanks to my eldest son for assisting with the shoot: it is hard to know where one is actually pouring the stuff when one’s head is flat on the table!
The water and paint mixture was definitely too dark and does not really work as imitation coffee, but it was far too messy to do re-shoot!
Post-processing: converted from RAW in PS Elements, cleaned up some drops on the table – and on my clothes! – then some levels and curves, but nothing much in terms of editing.