灰色

1. grey; ashy

♦ 一件~上衣 a grey jacket

2. pessimistic; gloomy

♦ ~人生观 a pessimistic (or grey) outlook on life

♦ ~的作品 a literary work pessimistic in tone

3. obscure; ambiguous

~市场 [经]grey market (unofficial market in shares before regular distribution)~系统理论 grey systems theory