https://www.kohls.com/product/prd-3511482/mens-cobalt-yellow-ion-plated-step-edge-band.jsp
Jewelry Nation Men's Cobalt Yellow Ion Plated Step Edge Band
Achieve a bold, yet simple look with this two-tone band, featuring a contemporary step edge.
cobalt yellowjewelrynationmen
https://www.christies.com/zh/lot/lot-6555376
PATRICK HERON (1920-1999), COBALT WITH RED AND YELLOW : AUGUST 1976 (VARIATION) | Christie's
COBALT WITH RED AND YELLOW : AUGUST 1976 (VARIATION)