Закрасить текстбоксы в разный цвет

Public Class Form3
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        setColors(0, 500)
    End Sub
    Private Sub setColors(ByVal vMin As Double, ByVal vMax As Double)
        Dim hMin As Integer = 0, hMax As Integer = 260
        Dim kf As Double = (hMax - hMin) / (vMax - vMin)
        For Each cnt As Control In Me.Controls
            If TypeOf cnt Is TextBox Then
                If cnt.Text = "" Then cnt.Text = vMin
                If CDbl(cnt.Text) < vMin Then cnt.Text = vMin
                If CDbl(cnt.Text) > vMax Then cnt.Text = vMax
                Dim hh As Integer = Math.Round(CDbl(cnt.Text) * kf)
                cnt.BackColor = HSVtoRGB(hh, 90, 100)
            End If
        Next
    End Sub
    Public Function HSVtoRGB(ByVal H As Integer, ByVal S As Integer, ByVal V As Integer) As Color
        Dim hue As Decimal = H
        Dim sat As Decimal = S / 100D
        Dim val As Decimal = V / 100D
        Dim r As Decimal
        Dim g As Decimal
        Dim b As Decimal
        If sat = 0 Then
            r = val
            g = val
            b = val
        Else
            Dim sectorPos As Decimal = hue / 60D
            Dim sectorNumber As Integer = CInt(Math.Floor(sectorPos))
            Dim fractionalSector As Decimal = sectorPos - sectorNumber
            Dim p As Decimal = val * (1 - sat)
            Dim q As Decimal = val * (1 - (sat * fractionalSector))
            Dim t As Decimal = val * (1 - (sat * (1 - fractionalSector)))
            Select Case sectorNumber
                Case 0, 6
                    r = val
                    g = t
                    b = p
                Case 1
                    r = q
                    g = val
                    b = p
                Case 2
                    r = p
                    g = val
                    b = t
                Case 3
                    r = p
                    g = q
                    b = val
                Case 4
                    r = t
                    g = p
                    b = val
                Case 5
                    r = val
                    g = p
                    b = q
            End Select
        End If
        r *= 255
        g *= 255
        b *= 255
        Return Color.FromArgb(255, CInt(Math.Round(r, MidpointRounding.AwayFromZero)), CInt(Math.Round(g, MidpointRounding.AwayFromZero)), CInt(Math.Round(b, MidpointRounding.AwayFromZero)))
    End Function
End Class

Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click
    Dim vv As New List(Of Double)
    Dim ii, jj As Integer
    Dim minColor As Color = Color.Green
    Dim maxColor As Color = Color.Red
    For Each cnt As Control In Me.Controls
        If TypeOf cnt Is TextBox Then
            If cnt.Text <> "" Then
                vv.Add(CDbl(cnt.Text))
                cnt.Tag = ii
                ii += 1
            End If
        End If
    Next
    ii = vv.IndexOf(vv.Min)
    jj = vv.IndexOf(vv.Max)
    For Each cnt As Control In Me.Controls
        If TypeOf cnt Is TextBox Then
            If cnt.Tag = ii Then
                cnt.BackColor = minColor
            ElseIf cnt.Tag = jj Then
                cnt.BackColor = maxColor
            Else
                cnt.BackColor = Color.White
            End If
            If cnt.Tag = jj Then cnt.BackColor = maxColor
        End If
    Next
End Sub

Private Sub Button4_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click
    Dim vv As New List(Of Double)
    Dim ii, jj As Integer
    Dim minColor As Color = Color.Green
    Dim maxColor As Color = Color.Red
    For Each cnt As Control In Me.Controls
        If TypeOf cnt Is TextBox Then
            If cnt.Text <> "" Then
                vv.Add(CDbl(cnt.Text))
                cnt.Tag = ii
                cnt.BackColor = Color.White
                ii += 1
            End If
        End If
    Next
    ii = vv.IndexOf(vv.Min)
    jj = vv.IndexOf(vv.Max)
    Dim tx = From tt In Me.Controls Where TypeOf tt Is TextBox AndAlso tt.tag = ii
    CType(tx(0), TextBox).BackColor = minColor
    tx = From tt In Me.Controls Where TypeOf tt Is TextBox AndAlso tt.tag = jj
    CType(tx(0), TextBox).BackColor = maxColor
End Sub

Private Sub Button5_Click(sender As System.Object, e As System.EventArgs) Handles Button5.Click
    Dim nBox As Integer = 11
    Dim v1, v2 As Double
    Dim vv(nBox - 1) As Double
    Dim nn(nBox - 1) As Integer
    Dim mode As Boolean
    For i = 0 To nBox - 1
        vv(i) = Val(CType(Me.Controls("TextBox" & i + 1), TextBox).Text)
        CType(Me.Controls("TextBox" & i + 1), TextBox).BackColor = Color.White
    Next
    v1 = vv(0)
    For i = 1 To nBox - 1
        v2 = vv(i)
        If v1 > v2 Then
            nn(i - 1) = 1
        Else
            nn(i - 1) = -1
        End If
        v1 = v2
    Next
    If v2 < v1 Then
        nn(nBox - 1) = -1
    Else
        nn(nBox - 1) = 1
    End If
    If nn(0) > 0 Then
        TextBox1.BackColor = Color.Red
        mode = True
    Else
        TextBox1.BackColor = Color.Green
        mode = False
    End If
    For i = 1 To nBox - 1
        If nn(i) > 0 AndAlso mode = False Then
            CType(Me.Controls("TextBox" & i + 1), TextBox).BackColor = Color.Red
            mode = Not mode
        End If
        If nn(i) < 0 AndAlso mode = True Then
            CType(Me.Controls("TextBox" & i + 1), TextBox).BackColor = Color.Green
            mode = Not mode
        End If
    Next
End Sub