Why should the facade of Hanyang District in Wuhan be uniformly painted gray?

Resistant to dirt and beautiful. According to the official account of Wuhan local treasure WeChat.

1, because gray is not dazzling, not reflective, unlike some red, yellow and green glare, but also resistant to dirt, so it doesn't need to be cleaned frequently, which can save a lot of money.

2, building exterior walls, such as all painted bright colors, will make people's visual fatigue, painted with this dark gray exterior wall is more eye-catching.