outline checkboxes in a Multi-row marker grid

i have a grid with "multi-row-marker" selection mode .. i need those checkboxes to have a red color border ..help !!
Also .. i am using a AW.Templates.Checkbox and i need it to have a red border .. defining the border color or border does not work .. what is the syntax ..

Try this one -

.aw-item-marker {border: 1px solid red;}