I can't find the quote as this present time, but the writers have said he is human. And in reference to a casual viewer, they would see red blood and instinctively say he's human. If they aren't overly familiar with the series, they won't be scrambling to fanboy arguments like "Well, they just filled an android up with red paint to fool Ripley".
Which brings me to point three: yes, it is in the film. Bishop says as much ("familiar face") and he bleeds red blood.