This example shows how to set the thumbnail background color using the Common Color dialog.
Private Sub mnuBackColor_Click()
On Error GoTo ErrColor
'Properties for the Common color dialog
CommonDialog1.CancelError = True
CommonDialog1.Flags = cdlCCRGBInit Or cdlCCPreventFullOpen
CommonDialog1.ShowColor
ImgThumbnail1.ThumbBackColor = CommonDialog1.Color
Exit Sub
ErrColor:
MsgBox Err.Description, , "Set Colors"
Exit Sub
End Sub