 <span class="o">=</span> <span class="kc">None</span><span class="p">,</span> <span class="n">KLCH</span> <span class="o">=</span> <span class="kc">None</span><span class="p">):</span>
<span class="w">    </span>
<span class="w">    </span><span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Calculate DE2000 color difference.</span>
<span class="sd">    </span>
<span class="sd">    Args:</span>
<span class="sd">        :xyzt: </span>
<span class="sd">            | ndarray with tristimulus values