Background color of the "Sort by" column

When the grid is initially displayed on the screen, I set the background color of the "Sort by" column. However, this color does not automatically adjust when I click on a different column.
.active-column-1 {background-color:threedlightshadow;}

How can I make the background dynamically change?

Current sort procedure assigns the CSS rule directly to the header template. Instead you need to apply it on the page stylesheet level to be able to implement the desired effect on the whole column. This looks like a good idea to me so I will try to add this to the grid as a standard feature.