Cor de burro quando foge I have edited this into the article hoping you won t remove it as original research First burro means ass not donkey jumento jerico or jegue in Portuguese Burro is the male hybrid of a donkey and a mare The female is a mula mule Actually the phrase does not refer to an undetermined colour but to a colour that CANNOT be determined since the ass has gone away It is a humorous definition of infalsifiability Moreover equine colours in Portuguese are a mess with a myriad terms that vary in definition from region to region and from animal to animal a baio horse is not the same color as an ass of the same color This adds difficulty to know the actual colour of a burro unless the animal is present