@Roy – Does the following snippet work for you (tested in InDesign CS5.5)?
Selection must be a text selection:
app.copy(app.selection[0]);
app.select(null);
app.paste();
var myNewTextFrame = app.documents[0].windows[0].activePage.textFrames[0];
myNewTextFrame.fillColor = "Yellow";
Of course, you could run into trouble, if the selection exceeds the current spread…
Uwe