many years ago, the scout troop did a weekend aboard the USS Yorktown. The boys loved it. They also toured a submarine and a Coast Guard ship too.
We were all surprised by the cramped, stinking quarters on the submarine, but what stood out with the boys was the latrine in the sub. A line of 8-9 poopholes with one painted RED, BLAIRING RED.
A long retired Petty Officer was asked why the seat was red.
Now, the boys were all about 12-15 years old, not exactly babes...
Well, he explained that when young men, not much older than them, engaged with social activities while on leave , some social women introduced them to burning sensations.... While infected with those diseases, they could only use the red seat, AND while treatment was continuing, their service time was extended.
The Petty Officer was informative and fatherlike but very direct.