Bill,
I thought you were only keeping Malaysian's? I see your signature is no longer included with your posts so I'm guessing the last time I saw it it was not up to date.
Regardless, the dark gray with yellow heads was one of my favorite phenotypes. I've only had one, a small male, I'll post a picture of it below.
Interesting story about this male. I was out of town several years ago when a 100 year flood hit the area I was living at the time and flooded my snake room with over 3' of water. Lost an incubator with a couple of clutches of Gonyosoma eggs and a few of my Gony adults were submerged underwater for nearly two hours. Surprisingly, none of them died from that but did die in the following months.
The male pictured below was small and in a rack that floated up and flipped over during the flood and he escaped. I was driving back and in constant contact with my brother in law who was trying to get my snakes to higher ground.
He informed me that this one escaped so I assumed it was long gone. He later called me and informed me he saw a snake swimming outside but could not tell the color. His brother came over and found it in a storage shed outdoors. It was very cold from being outdoors for several hours so it was easily captured. And yes, it was my dark gray male.
Every snake that was exposed to the water died within a few months despite my efforts to save them. Really set me back a long time. At any rate, here is the male:

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Currently keeping:
6.10 Gonyosoma oxycephala (Javan, mixed colors)
1.1 Philodryas baroni
1.0 Rhodesian Ridgeback