What does it mean to be yellow? Coward or what?

[Sylvie]

Test No. incompl/inter-2 "Like a red rag", question 8

As they turned round and ran away, people thought they were ..........

(a) red
(b) blue
(c) white
(d) yellow

Test No. incompl/inter-2 "Like a red rag", answer 8

As they turned round and ran away, people thought they were yellow.

Correct answer: (d) yellow

Your answer was: incorrect
As they turned round and ran away, people thought they were red.
_________________________

Hi,

I am little perplexed. I typed in "yellow" and it was marked as incorrect, with the correct answer being "red". Then, I looked at the teachers explanation, and it seems that "yellow" is correct after all. So what is the right color in this case?

Thank you,
Sylvie :-)

[Torsten]

Hi Sylvie,

Yellow is the correct answer.

TOEIC listening, photographs: An Asian boat pier

[Rich7]

And means coward in this sense.