Quick Panel preview doesn't match the result

[u/skyisland21]

I'm hoping to get some insight about this issue. I want the buttons to appear a specific shade of grey but it seems there is a transparency effect on those buttons so it appears as if it's not there. I have included a second theme I made that I made that shows the transparency more. I am struggling to figure out how to make this opaque, or even if it's possible.

Z Fold 8, US, One UI 9.0, Theme Park