Gamma Doppler uses a different color ramp (emeralds and greens) than classic Doppler. Emerald is the rare almost-solid green. Phases 1–4 are the bulk of listings.
Same rule as Doppler: Dust2pedia floor ≠ Emerald ask. Inspect the index before you treat a “Gamma Doppler” search result as the gem.
See also pattern index and overpay.