道歉信的英文模板可以參考以下內容：
Dear Sir/Madam,
I am writing this letter to apologize to you for the mistake that we sent the shoes in wrong color. I acknowledge that my fault has brought you great trouble and inconveniences. I hereby express my deep sorrow for this matter and we are going to do our best to make it up to you. I assure you that this mistake will not happen once again and would appreciate very much if you could give us a chance to show our sincerity on this matter.
Best regards,
[Your Name]
請根據具體情況調整上述模板內容。