When the two candidate entered into interview room, the interviewer asked “Tell me the color of the wall behind you”. Both of them answered green but one of them was rejected and other was selected.
They could have been facing opposite walls.
For example one is facing a green wall and the other one a blue wall. Then the one facing a blue wall waits long enough for the other one to answer green thinking they are both green, and after that deduces that the correct answer for him/her is green.
Asking the candidates what color the wall was...
..was just intended as a humorous icebreaker. (Obviously that would be a terrible way to pick your employees.) The candidate who was rejected showed limited competence in petrochemical engineering, which would have limited his ability to effectively communicate with customers in the target markets. The other candidate, in addition to demonstrating a surprising familiarity with deep-water drilling operations, was engaging and charming.
For what it's worth,
the wall was really more of an olive color.
When they entered the room, both candidates were facing a non-green wall. When they were asked the question, both turned 180°, looked at the wall color but...
First candidate then turned 180° again, answered, and was selected. OTOH, second candidate answered while still facing the green wall, and was rejected.
The one who got rejected
Looked behind to answer
The interviewer was probably testing
The candidate's skills to draw conclusion from what they have.
i.e. looking at the wall in front/side of them to deduce the colour of the wall behind them
The wall color is actually
The interviewer is aware of everything about the candidates, even their disorders (which is actually asked like every application nowadays), such as color blindness etc.
Because one candidate is
color blind and he/she cannot distinguish green and red,
so he/she intuitively answered as the wall is green and that answer is actually correct considering the color blindness.
The second candidate is not color blind and the interviewer is aware of that with the questionnaires asked before and he/she just confirmed the first candidates answer by telling the wall is green, and interviewer eliminated him/her just because of this.
did not happen immediately, as the rejected person is a parital colour-blind, who can recognize Green but perhaps not Red or Blue, which could be a requirement for the job ( which could have been found out by standard tests for such purpose)
There could be a doubt about "When the two candidate entered into interview room, the interviewer asked". If they'd just entered the room, one of them could be in front of the open door. The wall behind him would be the wall of the room leading to the interview room. The other candidate already in the middle of the room would answer correctly.
They were interviewed in different rooms, with different colored walls.