Background color of property manager page controls

How can I change the background color of a IPropertyManagerPageNumberbox like the ones in Hole Wizard that go yellow when you change the hole default values.
I have tried to cast the numberbox object to IPropertyManagerPageControl and use the BackgroundColor Property of it. But this did not help. Although when I use this method on labels it works just fine.

its a bug in their API, cannot be done at the moment.

Submit an SPR for it and post it here !

That’s how I know it cannot be done, it had one