While blackr is active you can press W to toggle the background color from white to black and back. Press F to toggle the frame around the photo on/off.

• 有四种书签列按钮可供选择，黑色背景、白色背景、含图框及不含图框。不过无论选择哪一个书签列按钮，皆可透过键盘快速键来切换四种效果。