This is a failed proposal. Consensus for its implementation was not established within a reasonable period of time. If you want to revive discussion, please use the talk page or initiate a thread at the village pump.

The scope of this project is to create a unified look on all template message boxes.

An idea would be to use a style similar to what Wikipedia:Article message boxes has produced, and then only do minor adjustments to their setup for correct hierarchy (like change css class ambox to messagebox-article or similar).