Enhancement: Different color for window with bell

As of now the only difference for a window with a bell is that the text gets bold, which is barely visible. I suggest changing the font color to make it more evident.

I did it in my configuration file (end of `dracula.sh`) by copying your line and changing it:

```tmux
set-window-option -g window-status-format "#[fg=#{?window_bell_flag,##ffb86c,##ffffff}]#[bg=#44475a] #I #W#{?window_flags,#[fg=##6272a4]#{window_flags},}"
```

with the relevant portion being

```
#{?window_bell_flag,##ffb86c,##ffffff}
```

which needs to have the colors reverted back to their names.

With this change, calling

```bash
echo -e '\a'
```

on a shell (possibly with a pause before it, or a command you want to be notified when it finishes) will make the window name change to orange. If you're working on another window while you wait, this will be much more obvious than a indistinguishable bold font.