Got focus has no properties - it is an event. For any object which has the backcolor property, you would need to use the GotFocus/LostFocus events, such as
Private Sub txAmt_GotFocus()
Me.txtAmount.Backcolor =
End Sub
What you'd put for the color would be one of the vb color constants, hexidecimal value (e.g. #FFFFFF) or perhaps one of the windows system color constants, but I've never used those in code. Use the LostFocus event to return the color to normal.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.