Hi,
If you use the standard <asp:GridView it is up to you to provide style for it in your CSS. We don't use the CSS adapters on the <asp:GridView because we want to keep it possible for you to use the default <asp:GridView. Instead we created <mp:mojoGridView which inherits from <asp:GridView and does use the CSS adapter. We include several pre-made themes for the mojoGridView that you can choose from in your style.config file and it is also possible to make your own theme from CSS and images.
In style.config you can see the available choices of included themes commented out, and only one is uncommented that is the one used in the skin:
<file cssvpath="/Data/style/gridview/ChromeBlackGridView.css" imagebasevpath="/Data/style/gridview/">none</file>
<!--
<file cssvpath="/Data/style/gridview/ChromeBlackGridView.css" imagebasevpath="/Data/style/gridview/">none</file>
<file cssvpath="/Data/style/gridview/ChromeGridView.css" imagebasevpath="/Data/style/gridview/">none</file>
<file cssvpath="/Data/style/gridview/GlassBlackGridView.css" imagebasevpath="/Data/style/gridview/">none</file>
<file cssvpath="/Data/style/gridview/SoftGreyGridView.css" imagebasevpath="/Data/style/gridview/">none</file>
<file cssvpath="/Data/style/gridview/WhiteChromeGridView.css" imagebasevpath="/Data/style/gridview/">none</file>
<file cssvpath="/Data/style/gridview/YahooGridView.css" imagebasevpath="/Data/style/gridview/">none</file>
-->
Hope it helps,
Joe