สอบถามเรื่องการเปลี่ยนสี ForceColor ของ Textbox

        .Textbox   /*LostFocus*/
        {
          font-size: 14px;
        }
       .Textbox:focus {  /*GotFocus*/
          border-color: #66afe9;
          outline: 0;
          -webkit-box-shadow: inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(102, 175, 233, .6);
                  box-shadow: inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(102, 175, 233, .6);
        }

<asp:TextBox ID="TextBox1" CssClass="TextBox" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox2" CssClass="TextBox" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox3" CssClass="TextBox" runat="server"></asp:TextBox>
...
...
...
TextBoxN

List<T> what = new List<T>();
Sort(Unknow Type);

Imports System.Drawing
Imports System.Windows.Forms

<ToolboxBitmap(GetType(TextBox))> _
Public Class AdvanceTextbox : Inherits TextBox

    'รับค่า/แสดงจำนวนจุดทศนิยม
    Public Enum TextBoxDisplayPrecisionScale As Byte
        None = 0
        One = 1
        Two = 2
        Tree = 3
        Four = 4
    End Enum

#Region "    Variables "

    Private _DisplayPrecisionScale As TextBoxDisplayPrecisionScale

#End Region

#Region "    Properties "

    <System.ComponentModel.DefaultValue(GetType(TextBoxDisplayPrecisionScale), "None"), System.ComponentModel.Category("Appearance")> _
    Public Property DisplayPrecisionScale() As TextBoxDisplayPrecisionScale
        Get
            Return _DisplayPrecisionScale
        End Get
        Set(ByVal Value As TextBoxDisplayPrecisionScale)
            _DisplayPrecisionScale = Value
            MyBase.TextAlign = HorizontalAlignment.Right 'จัดตำแหน่งชิดขวา
            Dim dblSubMybaseText As Double
            If String.IsNullOrEmpty(MyBase.Text) OrElse Not IsNumeric(MyBase.Text) Then
                dblSubMybaseText = 0
            Else
                dblSubMybaseText = CDbl(MyBase.Text)
            End If
            Select Case Me._DisplayPrecisionScale
                Case TextBoxDisplayPrecisionScale.One
                    MyBase.Text = String.Format("{0:N1}", dblSubMybaseText)
                Case TextBoxDisplayPrecisionScale.Two
                    MyBase.Text = String.Format("{0:N2}", dblSubMybaseText)
                Case TextBoxDisplayPrecisionScale.Tree
                    MyBase.Text = String.Format("{0:N3}", dblSubMybaseText)
                Case TextBoxDisplayPrecisionScale.Four
                    MyBase.Text = String.Format("{0:N4}", dblSubMybaseText)
                Case TextBoxDisplayPrecisionScale.None
                    MyBase.Text = String.Format("{0:N0}", dblSubMybaseText)
            End Select
        End Set
    End Property

#End Region

#Region "    Constructor "

    Public Sub New()
    End Sub

#End Region

    Protected Overrides Sub OnGotFocus(e As System.EventArgs)
        MyBase.ForeColor = Color.Orange
        'More...
        MyBase.OnGotFocus(e)
    End Sub

    Protected Overrides Sub OnLostFocus(e As System.EventArgs)
        MyBase.ForeColor = Color.Black
        'More...
        MyBase.OnLostFocus(e)
    End Sub

    Protected Overrides Sub OnValidating(ByVal e As System.ComponentModel.CancelEventArgs)
        Dim dblSubMybaseText As Double
        If String.IsNullOrEmpty(MyBase.Text) OrElse Not IsNumeric(MyBase.Text) Then
            dblSubMybaseText = 0
        Else
            dblSubMybaseText = CDbl(MyBase.Text)
        End If
        Select Case Me._DisplayPrecisionScale
            Case TextBoxDisplayPrecisionScale.One
                MyBase.Text = String.Format("{0:N1}", dblSubMybaseText)
            Case TextBoxDisplayPrecisionScale.Two
                MyBase.Text = String.Format("{0:N2}", dblSubMybaseText)
            Case TextBoxDisplayPrecisionScale.Tree
                MyBase.Text = String.Format("{0:N3}", dblSubMybaseText)
            Case TextBoxDisplayPrecisionScale.Four
                MyBase.Text = String.Format("{0:N4}", dblSubMybaseText)
            Case Else
                MyBase.Text = String.Format("{0:N0}", dblSubMybaseText)
        End Select
    End Sub

    'ปิดเสียง ปี๊ด เมื่อกดปุ่ม Enter
    Private Sub SetBeepOff(ByVal senser As Control, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown
        If e.KeyCode = Keys.Enter Then
            e.SuppressKeyPress = True
            SendKeys.Send("{Tab}")
        End If
    End Sub

End Class