Accessibility - Reflow-Mode - White font on a colored background

Hi to all!

I hope anyone can help me to solve my Problem with the Reflow-Mode for accessibility.

On one page of my document i have white font on a colored background - opened with the Reflow-Mode (Ctrl+4) i have white font on a white background.

How can i get a colored background to the Reflow-Mode for only this part of the document?

Is there a way to solve the problem?

I would be very grateful for your help!

Best regards

Verena