title: CSS - hsl or rgb(a) colors
body: <p>I am about to start a new project and I want its CSS to be both consistent and performant.
  I was wondering which color units I should use. <a href="https://medium.com/@fat/mediums-css-is-actually-pretty-fucking-good-b8e2a6c78b06" rel="noreferrer">Medium</a> and <a href="http://blog.trello.com/refining-the-way-we-structure-our-css-at-trello/" rel="noreferrer">Trello</a> have different approach advocating rba over hsl and vice versa. I am really struggling to understand the benefits of each other</p>
  
  <p>What are the pros/cons of hsl over rgb?</p>