Blue 2 vs White 2 steel for Japanese kitchen knives

Blue 2 (Aogami #2) and White 2 (Shirogami #2) are both Hitachi high-carbon steels, but Blue 2 adds chromium and tungsten to White 2’s base, giving it noticeably better edge retention while keeping similar sharpness. The trade-off is that Blue 2 is slightly more abrasion-resistant during sharpening, so it takes a little more time to refine an edge, whereas White 2 is easier to sharpen and can take a finer, more aggressive edge but dulls faster in use.