Maybe the creator had yellow food supplements in a capsule form and he made funny man of it in his head. Etc. Like Plato suggested: think of the image and it will be there (soon). It will be brought in reality. read more
In the movie, “Minions” the minions were evolved in the same way as the very early creatures on Earth. The funny part is that they can survive any severe conditions and lived for eternity probably. The creator of minions might have got the idea by the normal capsules and they're what they eat,therefore, they are coloured like bananas. read more