Colors for snacks highlights

Highlighting in [snacks picker](https://github.com/folke/snacks.nvim/blob/main/docs/picker.md) colors are incorrect. Looking at a [similar issue](https://github.com/folke/snacks.nvim/issues/874), it seems like it's a theme shortcoming.

<img width="519" height="232" alt="Image" src="https://github.com/user-attachments/assets/140f833c-e061-4e32-aff6-2c1d59613808" />