Public Class ColorDia
 
    Public Property title As String
        Set(value As String)
            Me.Text = value
        End Set
        Get
            Return Me.Text
        End Get
    End Property
 
    Public Property Color As Color
 
    Public WriteOnly Property CustomColors As List(Of Color)
        Set(value As List(Of Color))
            Dim max As Integer = Math.Min(value.Count - 1, 24)
            For i As Integer = 0 To max
                ColorLabels(i).BackColor = value(i)
            Next i
        End Set
    End Property
 
    Public Event ColorChanged(ByVal sender As Object, usercolor As Color)
    Private ColorLabels As New List(Of Label)
 
    Private red As New VScrollBar With _
        {.Parent = Me, .Left = 150, .Width = 30, .Maximum = 255, .LargeChange = _
        1}
    Private green As New VScrollBar With _
        {.Parent = Me, .Left = 190, .Width = 30, .Maximum = 255, .LargeChange = _
        1}
    Private blue As New VScrollBar With _
        {.Parent = Me, .Left = 230, .Width = 30, .Maximum = 255, .LargeChange = _
        1}
 
    Public Sub New()
        InitializeComponent()
 
        For i As Integer = 0 To 4
            For k As Integer = 0 To 4
                Dim loc As Point = New Point(k * 22, i * 22)
                Dim lb As New Label With _
                {.Location = loc, .Size = New Size(20, 20), .Parent = Me}
                lb.BackColor = Color.FromArgb(i * 50, k * 50, (i + k) * 25)
                AddHandler lb.Click, AddressOf LabelClick
                ColorLabels.Add(lb)
            Next k
        Next i
 
        Me.Text = "Farbauswahl"
 
        AddHandler red.ValueChanged, AddressOf ValueChanged
        AddHandler green.ValueChanged, AddressOf ValueChanged
        AddHandler blue.ValueChanged, AddressOf ValueChanged
 
    End Sub
 
    Private Sub ColorDia_Load(sender As System.Object, _
        e As System.EventArgs) Handles MyBase.Load
 
        Me.FormBorderStyle = Windows.Forms.FormBorderStyle.FixedDialog
        Me.Size = New Size(300, 200)
        Me.MaximizeBox = False
 
 
    End Sub
 
 
    Private Sub LabelClick(ByVal sender As Object, e As EventArgs)
        Color = DirectCast(sender, Label).BackColor
        RaiseEvent ColorChanged(Me, Color)
    End Sub
 
 
    Private Sub ValueChanged(ByVal sender As Object, e As EventArgs)
        Color = Color.FromArgb(red.Value, green.Value, blue.Value)
        RaiseEvent ColorChanged(Me, Color)
    End Sub
 
End Class

Private Sub Button1_Click(sender As System.Object, _
        e As System.EventArgs) Handles Button1.Click
 
     Using cd As New ColorDia
         AddHandler cd.ColorChanged, AddressOf colorchanged
 
         cd.title = "Demo zur farbauswahl"
         cd.Color = Color.Magenta
         cd.CustomColors = _
         New List(Of Color)(New Color() {Color.Red, Color.Yellow, _
         Color.Magenta})
 
         cd.ShowDialog()
 
         Me.BackColor = cd.Color
     End Using
End Sub
 
Public Sub colorchanged(sender As Object, usercolor As Color)
    Me.BackColor = usercolor
End Sub