One way to shed light on this would be to send a PM to the dev team of "Crush Depht". They are in contact with the real chief engineer of U-96, Friedrich Grade, who is 105 years old and a special expert for "CD".
Either the devs have already asked the LI about the lighting or they might do it.
https://www.subsim.com/radioroom/sho...d.php?t=247462