The phrase "do technicolor yawn" is a slang term for vomiting. It refers to the multiple colors and intensity of the vomit. There are several synonyms for this phrase that can be used depending on the context. Some of the common ones include hurl, puke, barf, upchuck, heave, retch, regurgitate, toss one's cookies, and spew. These synonyms are often used informally and are considered colloquial words. They can be used in everyday conversations or even in literature to convey emotions such as disgust or discomfort. Whatever word you choose to use, the meaning of the phrase will remain the same - to expel the contents of the stomach through the mouth.