changing bkg color

I'm trying to change the background color of my roku app.

I added the following line into the appMAIN.brs

Sub initTheme()
    ...
    theme.BackgroundColor = #EBEBEB

    app.SetTheme(theme)

End Sub

After running 'make' to zip the file when I try to side load it onto my roku I get the following error.
"Install Failure: Compilation Failed."

Where should I place the background color specification?

Thanks