A wind blew, from what quarter I know not, but it lifted the half-grown leaves so that there was a flash of silver grey in the air.

一阵风吹过， 我不知道是从哪里吹来的，但它吹起了半生不熟的叶子， 空气中闪过一丝银灰色。

You can recognize the genuine tape because of its silver grey color. The color was likely chosen because it closely resembles the color of the pipes the color of the pipes it would be used on.

你可以认出这种真正的带子，它是银灰色的。之所以选择这种颜色，很可能是因为它与管道的颜色相似。