This seems like an unfair question for non-football/soccer fans. Also, this is more of a “konglish” than real “korean” testing.
If you pay more attention to how we pronounce "blue" in English, you'll realize that we read it like this: bl-ue. The b and l sticks together, then the ue comes last. That's why in Konglish we say beul and lu. And you can say beu and lu, but it means brew. This is just my opinion. And if you wanna understand more about konglish, try saying the word in english slowly, and think of how Koreans would say it. That trick worked for me, i hope that can help.