Hi, just installed this awesome program on archlinux, I use as desktop environment xfce with a dark theme.
Here is what I see:

Unfortunately seems that the palette background follows the system color (is dark), but not the contained symbols.
All symbols have a fixed black foreground color; some have a transparent background, ad so aren't readable, some other have a fixed white background.
I think this could be an accessibility issue: if the symbols color is fixed, better fix also the palette background; otherwise, also the symbols should respect the system appearance colors.