Hi,
Please try with the below code snippet.
As per my knowledge there is not such type of property is there but you can assign CSS property by using below code snippet.
because for add button there are two DOM elements created.
<style type=
"text/css"
>
.RadGrid .rgAdd + a
{
//Add button text related css
}
.RadGrid .rgAdd
{
//Add button image related css
}
</style>
Do not forgot to add "!important" in CSS property.
Let me know if any concern.
Thanks,
Jayesh Goyani