Window switcher has low contrast when against dark background in light mode and vice versa

### What Happened?

Rectangle marking the chosen window has low contrast to the rest of the switcher, possibly due to transparency effect.

Dark mode against light background:

Light mode against dark background:

For reference, this is how switcher looks in light/light and dark/dark combinations:
Light mode against light background:

Dark mode against dark background:

### Steps to Reproduce

Switch windows in dark/light mode when background is light/dark.

### Expected Behavior

Rectangle marking the chosen window should be clearly visible.

### OS Version

8.x (Circe)

### OS Architecture

amd64 (on most hardwares)

### Session Type

Secure Session (Wayland)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell

```

### Hardware Info

_No response_