Meaning that when you wear a blue set of clothing, you show a pleasant image.
When another person looks at you, and you are wearing blue, they think that you are pleasant or pleasing to look at.
She looks good in that dress.
You look good with short hair.
You look good in a short hairstyle.
You look good in braids.
He looks good in a tuxedo.
My wife looked beautiful in her wedding dress.
She looks scary with that makeup.
It (the weather) looks nice today.
hope that helps. You should really look this up in a translation dictionary, it usually has a pretty direct translation to other languages I think.
Student or Learner