Collaborate with other modders to make Synthesia the way you want it.
Always the latest versions: [ colors.xml | ui.xml ]
Read the Getting Started topic to learn how important it is to MERGE YOUR CHANGES every time you download a new dev preview.
The next languages in line are Japanese and Korean. I don't expect to add a distinction between US and UK English. It would be extra effort for very, very little gain. (Sorry!)