Till (one) (is) blue in the face spoken language verb phrase
If you do something “till you are blue in the face”, you do it with many efforts but receive no or less success.
You can ask him till you are blue in the face, but he won't answer you.
I tried to explain to her till I was blue in the face, but she still got me wrong.
You can complain about it till you are blue in the face, but we won't change the decision.
He talked to her till she was blue in the face, but he couldn't convince her.
Permanently or finally
Forever or eternally
1. Used to indicate something lasts forever
2. Said when you believe something will never happen