1·Make sure your foreground colour is black. See image above.
确认你的前景色为黑色。详见上面图片。
2·Make sure that the foreground colour is black or whatever colour you want for the shadows.
确保前景色为黑色或者是你希望用做阴影的其他颜色。
3·Note how the background-color and foreground (type) colour are separated by a semi-colon. Be careful not to mix up the colons and semicolons or things will go horribly wrong.