Buff Laced is basically a gold laced with dominant white, making it that the "lacing" is white, the center of the feather is gold.
What you'd need to actually create such, for starters, are good quality, non-hatchery Wyandottes. Then, get one with dominant white genes, and one with gold lacing. Work there to get the white into the gold lacing.
Always remember though - Work on the type first, then the color. There are far too many Wyandottes out there that don't look anything close to the standard, and even the loved Blue Laced Red color variety, though not even accepted yet, can and has been ruined in a lot of birds, both in body and even color quality.
Although, I believe there are already some buff laced breeders out there. . .