Hi
You would have to use white as your original background color.
To access inside of each object that you refer to has slightly different code:
text box = xfa.resolveNode("Page1.Subform1.TextBox1.ui.#textEdit.border.fill.color").value = 255,255,255;
will set the inside of the text box white.
Replace'#textEdit' with the following for other objects:
Drop Down list = #choiceList
Date field = #dateTimeEdit
CheckBox = #checkButton
NumericField = #numericEdit
I am sure that you can also do this for radio buttons and if you really need it I can see if I can find out but I generally highlight the whole of the radio section using '.Page1.Subform1.RadioButtonGroup.fillColor = 255,255,255.
I hope that this helps. it took me a while to figure this out too!
Cheers
Darren