Private Sub UserForm_Initialize()
    With Me.ListBox1
        .MultiSelect = fmMultiSelectMulti
        .ListStyle = fmListStyleOption
        .AddItem "Красный"
        .AddItem "Синий"
        .AddItem "Желтый"
    End With
End Sub

Private Sub ListBox1_Change()
    Dim intI As Integer
    Dim str As String
    
    For intI =  0  To Me.ListBox1.ListCount -  1 
        If Me.ListBox1.Selected(intI) Then
            str = str & ";" & Me.ListBox1.List(intI)
        End If
    Next
    
    Me.TextBox1.Value = Mid(str,  2 )
End Sub