title: Color reduction with ImageMagick
body: <p>There's an image I convert to grey in a first step using this:</p>
  
  <pre><code>convert out.jpg -colorspace GRAY -normalize png:out.png
  </code></pre>
  
  <p>In another step I would like to reduce colors to 12:</p>
  
  <pre><code>convert out.png +dither -colors 12 -filter box -normalize png:out.png
  </code></pre>
  
  <p>This works perfectly with a very old version of GraphicsMagick which I have installed on one machine. On another machine is the latest version of ImageMagick. Here the resulting image just has 8 colors.</p>
  
  <p>Is there a way I can force ImageMagick to make exactly 12 colors? Not more, not less?</p>