Is my dislike of the color and engravings on the cover of the Mushaf considered an insult to the Qur’an, and will anything befall me or is repentance obligatory upon me, and must I force myself to like it?

There is no accountability for a servant concerning self-talk unless they act upon it or speak it, and this is not considered an insult to the Quran, due to the Prophet, peace and blessings be upon him, saying: "Indeed, Allah has forgiven my nation for what they merely think to themselves, as long as they do not act upon it or speak of it." And the fact that the inscription did not please the questioner does not affect his faith, for people differ in their circumstances regarding the beauty of handwriting. They used to write the Quran on scrolls and tablets, and no one ever mandated that every script it is written in must be aesthetically pleasing. Rather, what is obligatory is to love the Quran and act upon its rulings.