How to change extjs grid row color

I want to change the color of the row in a ex开发者_如何转开发tjs-3.1 grid from default to "dark red", When i either hover my mouse on row or i select a row , Please help.

.x-grid3-row-selected {    
    background-color:red !important;
}

This will change the selected color to red.

You can do it by setting the background color of each column's renderer function.