title: How to apply theme to jupyter lab
body: <p>I tried to apply dark theme by putting a *.css file in the ~/.jupyter/custom/ directory (like <a href="http://sherifsoliman.com/2016/01/11/theming-ipython-jupyter-notebook/" rel="noreferrer">here</a>). This changes a theme for a normal jupyter notebook. But no affect on the jupyter lab appearance. I also tried to install a theme using jupyter-theme, but alas, no changes in jupyter lab appearance. </p>
  
  <p>Can someone point me to the how-to guide?</p>