The only active pakset developer dealing with vehicle models at present is me, and it is likely to be many years before the modern liveries of the class 319 top my list of priorities. I should note that shading and anti-aliasing these graphics correctly would take more work than starting from scratch, as using the 3d models is much easier than pixel painting.
If you wish to add further vehicles/liveries of your own choosing and at your own pace, and you are very welcome to do so, you will need to learn the complete process so that all that I need to do is merge the files into the main directory and test them, or else you are not so much making things yourself as asking me to make them.
Edit: I have now added the detailed step by step tutorial on how to make additional liveries for existing vehicles properly
here. I strongly suggest that you follow this tutorial to learn how to do what you want to do.