Color help please!

[Blackwater Farm]

Just picked up this new driving pony, (sorry not a mini guys!) and I have a bit of a color question. This is Buttermilk, a 12 year old, 43" pony gelding. I am about 90% sure that his base color is gold champagne. He has hazel eyes and mottleing/freckling of the skin around the eyes, nose, mouth, sheath, rear and he also has a blaze. My question is about this dark spot on his side. Possible chimera or somatic mutation?? Thats the only thing I can think of. Or maybe the worlds largest Bend Or spot (LOL)! He has no pinto or appy spots that I can see. Let me know what you guys think! Thank you! P.S. - It wasnt me that chopped his tail off! He came to me that way! They also chopped his mane and forelock the poor fella!

 

[chandab]

Interesting. I have no idea, about the only thing I can think of is the marking called "Bloody shoulder", but I don't know what pattern its linked to. I'm sure if you google it, you'll find something.

 

[countrymini]

According to my Equine Colour Genetics book, marks like these that are not related to any other colour trait are usually classed as birthmarks and can't be passed on. That might not be what it is but just a suggestion from the book.

 

[targetsmom]

I wonder if this could be a "bloody shoulder marking"??? Google it for examples.

 

[countrymini]

http://www.whitehorseproductions.com/ecg_basics4.html

 

[Blackwater Farm]

I dont think it can be Bloody Shoulder, that forms on grey horses only. I think it has to be a somatic mutation of some kind. I know that a gold champagne is a genetically red horse with the addition of the champagne gene. Seeing the spot is red and the rest of him is gold champagne, I think maybe the Ch gene might have forgotten about this one patch!!!! Thanks everyone for your help!!! Thanks countrymini for that link!