ColourPicker_ReadDialog does not return NoneSelected-State correctly

I have the impression that ColourPicker_ReadDialog does not return the correct state of the NoneSelected option button. When I call ColourPicker_ReadDialog and look at the flags of the colour picker block they do not seem to be updated when I select/deselect the “None” button while the dialog is open. However when I use ColourPicker_UpdateDialog and change the state on the NoneSelected button this is reflected in the ColourPicker_ReadDialog result. So ColourPicker_UpdateDialog seems to work as expected but manually changing the state does not. Colour and selected model seem to be read correctly.