Which early coat colors were present in the farm dogs before the standardization fixation on wheaten?

Dark brindled, brown, red, and even black.

The Soft-Coated Wheaten Terrier, in its original utilitarian phase on the Irish farmstead, exhibited a wide variation in coat pigmentation, focusing entirely on function rather than aesthetics. While the breed is globally recognized today for its characteristic golden wheaten shade, early records indicate a spectrum of colors existed among these working dogs. This palette included darker variations such as dark brindled patterns, shades of brown, striking red coats, and even pure black. The acceptance of this diversity underscores the principle that any coat providing adequate protection against the damp Irish weather and thorny environment was deemed functional and therefore acceptable for breeding purposes, contrasting sharply with the later focus on a single, standardized golden hue.