Sears Special Run
#495091 Stablemate Assortment
The colour on this particular special run has been referred to in several Breyer guides as "Olive Dun". Though he certainly possesses a green tint, he lacks the two most characteristic dun traits: leg barring and a dorsal stripe. The leg barring isn't always seen on a dun horse, but the dorsal stripe is standard. These models do often have fuzzy, dark shading down the back, but it usually appears more like counter-shading, an effect of the sooty gene which gives his body that smudgy black shading.
Whatever you call this colour, sooty buckskin or dun, breed assignment is a bear as you not only have to work with his body type - extremely stocky with clean legs - but you have to find a breed or combination which can give you the cream gene (the gene which causes buckskin and palomino) or the dun gene you would need to explain his colour.
On the rare occasions I show my model, I have him listed as a French-bred Percheron (which tend to be heavier than American-bred Percherons) x American Cream Draft Horse. Despite the name, American Creams' golden colouring comes from the champagne gene acting on a chestnut coat; they are not palominos. Cream, though rare, does exist in the gene-pool, though. It's a long-shot as a breed assignment, but not impossible.
Though a lighter draft type, North Swedish Horses also carry cream, so a cross with this breed and a heavier draft type could work. If you are going for the dun option, be skeptical of breed profiles which list 'dun' a legal colour, as the terms buckskin and dun are used as interchangeably in Europe.