Most of the so called reference photos that's been posted here are ONLY good for what it is. The lighting condition throws the actually look off by a mile and most of the people don't know about that stuff since not everyone's trained to know how to look and where to look. If anyone want's to actually go with any those "references" flat out doesn't know what their doing, sorry. That's if you really want something that's....right.
There's really not much of debate as to how the thing should be painted. There're only the Stan Winston Studio or the ILM versions(not preferred). Since this piece is sourced from the Stan Winston Studios. It should go with how the studio painted it originally.
Paul and his team will be calling the shots on how they are going to be painted. They have more then enough references to do the job.
With that said. Here's the look of the screen used 1/1 head. A set of low res reference worthy photos in my book. Most of the stuff on google are just not worthy to even be mentioned. By tweaking the expose will reveal more details and color.