Text is white and unreadable

How can i change the text under the image so visitors can read it? Can i also change the size of the text?  Now the text is white on a white background.
Hertogelijke Heemkundige Kring het Land van Beveren - Pas verschenen

Hi Johnny,
Could you please try the following steps in Edocman and let us know the result?
- Go to Configuration.
- Open the Themes tab.
- In the Select Theme Type field, choose the Dark Layout option.
- Save the changes and test to see how it works.
Please let us know if you encounter any issues or if the dark theme displays as expected.
Thank you for your cooperation!
Dam

Dear Mr Dam, thanks for the quick response I allready tried the dark theme but then the text of the categories isn't readable than it is dark text on a dark background:
www.landvanbeveren.be/tijdschriften

Hi Johnny,
Could you please submit ticket on category: Edocman and provide your css issues, we will help you to solve those issues directly.
Thanks
Dam