A control's SystemColorsChanged event fires when the system's colors change. You can use that event to update your application's colors. (Admitedly this seems like a low-priority exercise for most applications.)

Private Sub SetControlColors()
    Label1.BackColor = _
        Color.FromKnownColor(KnownColor.ActiveBorder)
    Label1.Text = "ActiveBorder"

    Label2.BackColor = _
        Color.FromKnownColor(KnownColor.InactiveBorder)
    Label2.Text = "InactiveBorder"

    Label3.BackColor = _
        Color.FromKnownColor(KnownColor.ActiveCaption)
    Label3.Text = "ActiveCaption"

    Label4.BackColor = _
        Color.FromKnownColor(KnownColor.ActiveCaptionText)
    Label4.Text = "ActiveCaptionText"

    Label5.BackColor = _
        Color.FromKnownColor(KnownColor.InactiveCaption)
    Label5.Text = "InactiveCaption"

    Label6.BackColor = _
        Color.FromKnownColor(KnownColor.InactiveCaptionText)
    Label6.Text = "InactiveCaptionText"

    For Each ctl As Control In Controls
        Dim brightness As Integer = _
            CInt(ctl.BackColor.R) + _
            ctl.BackColor.G + _
            ctl.BackColor.B
        If brightness > 300 Then
            ctl.ForeColor = Color.Black
        Else
            ctl.ForeColor = Color.White
        End If
    Next ctl
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal _
    e As System.EventArgs) Handles MyBase.Load
    SetControlColors()
End Sub

Private Sub Form1_SystemColorsChanged(ByVal sender As _
    Object, ByVal e As System.EventArgs) Handles _
    MyBase.SystemColorsChanged
    SetControlColors()
End Sub