▁the ▁ch icken ▁( G all us ▁gall us ▁dom est icus ) ▁character ized ▁by ▁a ▁uniform , ▁pale ▁bl u ish ▁grey ▁color ▁across ▁all ▁fe athers . ▁The ▁distinct ive ▁color ▁is ▁caused ▁by ▁the ▁action ▁of ▁an ▁aut os om al ▁re cess ive ▁gene , ▁commonly ▁designated ▁as ▁" lav ", ▁which ▁reduces ▁the ▁expression ▁of ▁e um el an in ▁and ▁ph ae om el an in ▁so ▁that ▁black ▁areas ▁of ▁the ▁pl um age ▁appear ▁pale ▁grey ▁instead , ▁and ▁red ▁areas ▁appear ▁a ▁pale ▁buff . ▁ ▁Description ▁ ▁The ▁" lav ender " ▁gene ▁( lav ) ▁in ▁the ▁ch icken ▁causes ▁the ▁dil ution ▁of ▁both ▁black ▁( e um el an in ) ▁and ▁red / b rown ▁( pha e om el an in ) ▁p ig ments , ▁so ▁according ▁to ▁color ▁background , ▁dil ution ▁due ▁to ▁" lav ender " ▁gives ▁a ▁sort ▁of ▁pl um age ▁color ▁patterns : ▁On ▁an ▁extended ▁black ▁background , ▁this ▁condition ▁causes ▁the ▁entire ▁surface ▁of ▁the ▁body ▁an ▁even ▁sh ade ▁of ▁light ▁sl aty ▁blue , ▁which ▁is ▁the ▁typical ▁phen ot ype ▁known ▁as ▁'" self - blue " '. ▁ ▁On ▁a ▁red / b rown ▁color ▁pl um age ▁background , ▁lav ender ▁gene ▁de gr ades ▁color ▁to ▁be ige , ▁like ▁in ▁some ▁P ek in ▁B ant ams ▁as ▁in ▁the ▁picture ▁set ▁aside . ▁On ▁the ▁color ▁background ▁of ▁the ▁Belg