Public Class Class1
    'das hier geht
    Public Const test1 As Boolean = True
    Public Const test2 As String = "teststring"
    Public Const test3 As FormBorderStyle = FormBorderStyle.None
    'das hier nicht - warum ?
    Public Const test4 As Color = Color.Aqua
End Class

Dim c As Color = Class1.test4