enabling syntax hi for modified buffers

[rzjfr]

Although having a star * flag at the end of the modified buffers (current situation) is a good enough feature for those with set hidden in their vimrc, it was a bit hard for me to find them on the screen without having a different color than the other tabs. I thought maybe some other Vem Tabline user might also expect more from the modified and left alone buffers in terms of making themselves more visible to the user. Mines look like this now:

only tested on terminal vim with a certain colorscheme