unobtrusive
adj
(usuapprov 通常作褒义) not too obvious or easily noticeable; not drawing attention to itself or himself; discreet 不太显著的; 不引人注目的; 不招摇的; 谨慎的
an unobtrusive but pleasing design 悦目而不扎眼的图案
He was so quiet and unobtrusive that you would hardly know he was there! 他很文静, 简直注意不到他在那儿!