With the new Innovate theme, search text on a slicer shows up with a white font color on a white search background. Seems like the background of the search part of the slicer isn't
I have made a test but couldn't reproduce your issue, the text color is black and can be seen on my side.
If possible, could you please share a sample pbix(please do not upload your original file) for further test?
Here's a link to download the PBIX.
Are you using the Innovate theme that was just added in the September release? Your colors seem much lighter than the ones pictured in my initial post.
On my side, the text can be seen, please check if power bi desktop has been updated to the latest version.
I'm on the latest build from the Store
I've published the same test report online and it's still showing the same issue.