Unobtrusive (adjective)

1. Not drawing attention to oneself; subtle.
2. Not likely to cause offense or disturbance.

Origin:

Mid 19th century: from un- (expressing negation) + obtrusive.

Examples:

1. The music was unobtrusive and provided a pleasant background.
2. The camera is small and unobtrusive.
3. He tried to be unobtrusive and not interrupt their conversation.
4. The decor is unobtrusive and allows the paintings to be the focal point.
5. An unobtrusive service that runs in the background.