The word "striking as" is often used to describe something that is noticeable, impressive, or catches one's attention. However, antonyms for this phrase might include words such as dull, ordinary, unremarkable, or unmemorable. These antonyms suggest that something is not particularly outstanding or noteworthy, and may blend into the background or be easily forgotten. Other antonyms might include subtle or understated, indicating that something is not bold or showy, but rather more muted or restrained in its appearance or effect. Ultimately, the choice of antonym depends on what qualities one wishes to emphasize in describing a given object, person, or idea.