Our toddler was amazed when he was served some yellow string beans once because, to that point, he had only seen green string beans (which he called “greenie beanies”). He loved them and always asked for “yellow greenie beanies” after that. Since then, yellow string beans have always been called “yellow greenie beanies” in our house.
English is not my dad’s first language, so idioms could be confusing. When he was dating my mom, he once told her not to look for a gift in the horse’s mouth. That has stuck.