hide and reveal content on OneNote

[AMN]

Hi,
on OneNote:

Is there a way to hide a bit of content temporarily?
Scenario: during a lesson (am a teacher), I would like to have the answers available, but not visible straight away.
Or there might be a diagram, or some hints I want to have ready but only reveal after a while (i powerpoint, animation does the trick).
In OneNote, the next best thing I have found is to hide content with a coloured rectangle, and then I can delete the rectangle, revealing hidden content.

Is there a way to create such filled coloured rectangle within OneNote or do I have to create it on powerpoints, and then copy/paste it?
I have seen how to add a frame (by drawing a rectangle) but they are transparent.

thanks.