Silver Cuckoo / Golden Cuckoo
A variant of Marans (Gallus gallus domesticus)

Representative Maransphoto — a dedicated image of this exact morph isn't available yet.
Cuckoo barring overlaid on a silver (cool, contrasty) or golden (warm gold-tinged neck/saddle) ground. The two ground colors of the classic cuckoo Marans.
Keeper tips for this variant
Golden Cuckoo cockerels can show messy brassiness — select for clean, even gold in the hackle if breeding to standard.