I am assuming you want to create your own ThemePack assembly that will work like the external ThemePacks included with NA for WPF (i.e. ForestGreen). If you simply want to restyle the Grid, you can do so using the standard Styling infrastructure of WPF -- overriding the default control Styles with Styles you've customized.

Either way, you'll likely want to start with the DefaultStyles included with the product. Check out this post for some background on the DefaultStyles: http://forums.infragistics.com/forums/p/1563/14702.aspx#14702 

Once you're finished with that post, there is a section in the NetAdvantage for WPF Help entitled Creating a ThemePack that steps through the creation of a ThemePack assembly:

http://help.infragistics.com/NetAdvantage/WPF/2007.1/CLR3.x/

Developer's Guide > Styling Your Application > Creating a ThemePack

In response to your post the following URL appears to be broken - http://help.infragistics.com/NetAdvantage/WPF/2007.1/CLR3.x/

I am looking for info on creating my own theme and have started out with default styles having modified those, however my problem is that certain records mean different things and these need to be reflected in a particular colour and when you hover over ithighlights in that colour that the record text is set to... bit confusing - basically I need to add multiple colours and hover states to a single grid... help!