The phrase "gay up" is considered offensive and is used derogatorily in some circumstances. Therefore, it is recommended to use alternative, more inclusive phrases. Some synonyms for "gay up" include "brighten up," "lift the mood," "make more festive," or "add more color to." These phrases are more inclusive and do not stereotype or offend any particular group of people. It is important to choose language that is sensitive and respectful to everyone, regardless of their sexual orientation or gender identity. By doing so, we can create a more inclusive and welcoming environment.