.net – Remove Border On Focus From Button Control

I am setting my Winforms Button control properties to appear as a hyperlink would on a web page. I've formatted everything fine, except the border in the FlatAppearance object. I have code to act as pseudo-CSS (FormBackColor is a string constant.):

b.FlatStyle = FlatStyle.Flat
b.BackColor = ColorTranslator.FromHtml(FormBackColor) 
b.ForeColor = Color.Blue
b.Font = New Font(b.Font.FontFamily, b.Font.Size, FontStyle.Underline)
b.Cursor = Cursors.Hand

Dim fa As FlatButtonAppearance = b.FlatAppearance
fa.BorderSize = 0
fa.MouseOverBackColor = b.BackColor
fa.MouseDownBackColor = b.BackColor

AddHandler b.MouseEnter, AddressOf ButtonMouseOver
AddHandler b.MouseLeave, AddressOf ButtonMouseOut

Here are the mouse out/over functions as a reference to what is going on:

Public Shared Sub ButtonMouseOver(ByVal sender As Object, ByVal e As EventArgs)

    Dim b As Button = DirectCast(sender, Button)

    Dim fa As FlatButtonAppearance = b.FlatAppearance
    fa.BorderSize = 1

End Sub

Public Shared Sub ButtonMouseOut(ByVal sender As Object, ByVal e As EventArgs)

    Dim b As Button = DirectCast(sender, Button)

    Dim fa As FlatButtonAppearance = b.FlatAppearance
    fa.BorderSize = 0

End Sub

The code removes the border from the flat Button control except on MouseOver, where I add a 1 pixel border. On MouseLeave, I remove the border. This is to show some visual feedback. This works fine when the button does not have the focus. However, if I click on the button, giving the button focus, mousing out and over again now shows a greater than 1 pixel border around the button. I'm imagining it's combining my button's explicit 1 pixel border with the traditional "Winform Button has the focus, so add a border" border around the Button.

How can I disable/remove the "Winform Button has the focus, so add a border" border? Or, should I just do a check in ButtonMouseOver to check if the control has the focus, being a condition of adding the border, and just be done with it? I'd prefer to remove the automatic border from focus for whatever reason 🙂