Now, I've never understood all these colors in the mini world. To me, that's a sorrell horse (MAYBE a chestnut, but to me those are just sorrell horses, too). I don't see the flaxen mane & tail. I'm sure he'll turn out to be some fancy something color, but I don't understand it all.
I'd have to say this guy is most definitely carrying silver, but telling what else is there for coloring is difficult. It seems like the sun is affecting his body coloring also. I would guess liver chestnut with silver, or a very deep bay with silver maybe as his base coloring since he appears so much darker than most silver dapples.
Silver does not express on Red, only Black. There would be no way of telling if he carried Silver, and, even if you were to accept that some people can usually tell, it is a personal opinion and he carries none of the "markers" suggested, such as a very blonde mane and tail etc.
I do not even see a Liver Chestnut, just a rich sorrel.