ic ▁cre ams . ▁A ▁certain ▁percentage ▁of ▁dark ▁bay , ▁se al ▁brown , ▁and ▁black ▁horses ▁exhib it ▁such ▁subt le ▁dil ution ▁of ▁their ▁co ats ▁as ▁to ▁be ▁mis register ed . ▁In ▁the ▁study ▁that ▁mapped ▁the ▁cre am ▁gene , ▁three ▁horses ▁registered ▁as ▁se al ▁brown , ▁dark ▁bay ▁or ▁bay ▁were ▁actually ▁sm ok y ▁black ▁and ▁bu ck sk in . ▁This ▁is ▁one ▁way ▁by ▁which ▁the ▁cre am ▁gene ▁is ▁transm itted ▁through ▁gener ations ▁without ▁being ▁identified . ▁H ors es ▁born ▁pal om ino , ▁bu ck sk in , ▁and ▁sm ok y ▁black , ▁but ▁also ▁carry ▁the ▁gray ▁gene , ▁have ▁a ▁hair ▁coat ▁that ▁turns ▁white ▁as ▁they ▁age ▁and ▁are ▁usually ▁registered ▁as ▁" gray " ▁rather ▁than ▁as ▁their ▁birth ▁color . ▁ ▁This ▁is ▁particularly ▁a ▁common ▁occurrence ▁in ▁the ▁Con nem ara ▁bre ed . ▁ ▁H ors es ▁sold ▁after ▁turning ▁fully ▁gray ▁may ▁surprise ▁bre ed ers ▁by ▁producing ▁golden ▁or ▁cre am ▁off spring . ▁ ▁This ▁effect ▁- ▁stronger ▁expression ▁on ▁red ▁p ig ment ▁- ▁is ▁also ▁seen ▁in ▁coat ▁pattern ▁gen es ▁in ▁horses . ▁In ▁general , ▁white ▁mark ings ▁are ▁more ▁per vas ive ▁in ▁ch est n uts ▁than ▁in ▁non - ch est n uts , ▁to ▁the ▁extent ▁that ▁hom o zy g ous ▁non - ch est n uts ▁( which ▁carry ▁the ▁" Extension " ▁( E ) ▁gene