▁the ▁shield ) ▁and ▁neck , ▁blue ▁fe athers ▁on ▁the ▁breast , ▁and ▁pur pl ish - blue ▁fe athers ▁on ▁the ▁shoulders , ▁back , ▁sc ap ular ▁and ▁less er ▁cover t ▁fe athers . ▁Some ▁of ▁the ▁rect rices ▁( tail ▁fe athers ) ▁are ▁pur pl ish - b rown , ▁and ▁some ▁of ▁the ▁sc ap ular ▁fe athers ▁and ▁those ▁on ▁the ▁mid - back ▁are ▁so oty - b rown ▁at ▁the ▁base ▁and ▁so oty - blue ▁further ▁up . ▁The ▁central ▁rect rices ▁are ▁so oty - b rown ▁and ▁bl u ish . ▁This ▁colour ation ▁indicates ▁that ▁the ▁Liverpool ▁spec imen ▁was ▁a ▁younger ▁bird ▁than ▁the ▁Vienna ▁spec imen , ▁and ▁the ▁latter ▁had ▁reached ▁the ▁final ▁stage ▁of ▁m atur ity . ▁Since ▁the ▁Liverpool ▁spec imen ▁pres erves ▁some ▁of ▁its ▁original ▁colour , ▁van ▁Gr ouw ▁and ▁H ume ▁were ▁able ▁to ▁re construct ▁its ▁natural ▁colour ation ▁before ▁becoming ▁white . ▁It ▁differ ed ▁from ▁other ▁sw am ph ens ▁in ▁having ▁black ish - blue ▁l ores , ▁fore head , ▁crown , ▁na pe ▁and ▁h ind ▁neck , ▁pur ple - blue ▁mant le , ▁back , ▁and ▁wings , ▁a ▁dark er ▁r ump ▁and ▁upper - tail ▁cover t ▁fe athers , ▁and ▁dark ▁grey ish - blue ▁under parts . ▁ ▁Phill ip ▁gave ▁a ▁detailed ▁description ▁in ▁ 1 7 8 9 , ▁possibly ▁based ▁on ▁a ▁live ▁bird