A little later, the faint blue glow of the emergency lights went out.

稍过一会，应急灯微弱的蓝光熄灭了。

youdao

The curvature of the Earth’s horizon (the limb) is clearly visible, as is the faint blue line of the upper atmosphere directly above it (at image top center).

地球地平线的曲线（周边）清晰可见，它的正上方隐约显现出高层大气的蓝线（图片中上部）。

youdao

The curvature of the Earth's horizon (the limb) is clearly visible, as is the faint blue line of the upper atmosphere directly above it (at image top center).

地球地平线的曲线(周边)清晰可见，它的正上方隐约显现出高层大气的蓝线(图片中上部)。

youdao

The sky beyond is washed with strokes of cobalt and cerulean blue, and a faint but perceptible smell of aniseed and wild garlic hangs in the air.

BBC: The three colours of Ibiza