I usually look at the monitor, not the case under the desk. ;)

That said, I don't want RGB bleed, nor do i want a case where I see the insides. The computer is there to be powerful and discreet (both when it comes to noise and looks).

But sure, you could skip the walnut. I think Noctua should also go well with lighter woods. Oak perhaps but probably not all the way to birch.