That's the "Christmas Tree" display showing all watertight doors, engine intake vents, any way that sea water could get into the people tube. More than four out of five submarine commanders agree that seawater should normally be kept out of the people tube. When the lights all green the submarine is rigged for dive.
Now I'm curious about how you want to change the colors and why. (As an American I reserve the right to massacre any language on Earth to suit my fancy, and that includes English itself!)
