title: What colors mean on storyboard interface builder constraints
body: <p>I have constraints on the storyboard with different colors, and just want to know what they all mean, and what the errors are.  Eg:</p>
  
  <p><a href="https://i.stack.imgur.com/UkzBR.png" rel="noreferrer"><img src="https://i.stack.imgur.com/UkzBR.png" alt="enter image description here"></a></p>