[S] Source of a Greek book cover in a nappy advert

While trying to decipher what the book's language is, it turns out that the book's title might be "Μαθαινω Τα Χρωματα", which roughly translates to "Learn the Colours", which sounds plausible considering the kids on the cover appear to be looking at a rainbow. I still haven't found the exact cover, but hopefully I'll keep looking.