How to make your web pages to black and white

1.2020 on April 4 this special day, the day before - Lead State Council decided to hold a national mourning April 4 2020

At the same time the major sites also expressed his condolences to stop taking more color to the site condolences to black and white

Full of curiosity about the investigation how the site into a black and white pages here to share

Change the color of all the pictures in black and white (100% gray): put your pages can be placed css properties: grayscale: a grayscale mean

*{
过滤属性
}

filter: grayscale(90%);

2. casually looking for a web developer to use debug mode it displays