How do you get rid of Minecraft strokes?

Bo
3

I accidentally pressed a key and now I can see which yellow, red or blue lines help me to see things better. So if there's a monster in front of me, it is surrounded by a white box. Does anyone know how to do that?

Al

You have to press the "F3" key and B at the same time then it should go away

Co

Hold down F3 while pressing B. But be sure to press F3 first.

gl

F3+ B

Sometimes also Fn + F3+ B

With F3+ Q (or Fn + F3+ Q) you can see further key combinations with F3