title: How to define BGR color range? Map color code to color name
body: <p>I want to create color mapping, define few color names and boundaries in range of which those colors should fall. For example (BGR format), </p>
  
  <pre><code>colors = {
      'red': ((0, 0, 255), (125, 125, 255)),
      'blue': ((255, 0, 0), (255, 125, 125)),
      'yellow' ....
  }
  </code></pre>
  
  <p>So if I receive color, let's say (255, 50, 119) I can call it blue. I want to make such mapping for at least colors of rainbow plus gray, black, white. Using Python and openCV. </p>
  
  <p>The problem is that I don't really understand where to get those values for boundaries, is there kind of lowest / highest value for blue, red and so on?</p>