argue/talk etc till you're blue in the faceinformalLOT/LARGE NUMBER OR AMOUNT to argue, talk etc about something a lot, but without achieving what you want 费尽唇舌,嘴巴说干了都没用 You can tell them till you’re blue in the face, but they’ll still do what they want. 你就算费尽唇舌,他们还是会独断独行。
→ argue/talk etc till you’re blue in the face at blue1(1)