With a project hosted on SVN that has a versioned material:
- select the material in the Project browser
- change the main color
- select the material in the default outgoing changeset and press submit
- add a description and press save
You will be asked if you want to add the .meta file for the material to the server (seems like the meta file was actually for the folder where the material is in)
- select yes

result: Version Control General: Failed to start process '"C:\Program Files\TortoiseSVN\bin\svn.exe" add --depth=empty "E:/localSvnTest/project/Assets" "E:/localSvnTest/project/Assets/Materials.meta"' exit code 1