JSFiddle - React, Tailwind, and code Playground

HTML

<button id="showColor">Colorpicker</button>
<div class="colorWrap">
<p class="disclaimer">Let op! De kleuren kunnen er een beetje anders uitzien dan op het voorbeeld</p>
<ul>
    <li>
        <div class="box" style="background-color: #d6c794; color: #000000" onclick="setRalOption('1000','D6C794','0');return false;"> <a href="#" style="color:inherit;">RAL1000</a>

            <br><span class="color">D6C794</span>

        </div>
    </li>
    <li>
        <div class="box" style="background-color: #d9ba8c; color: #000000" onclick="setRalOption('1001','D9BA8C','0');return false;"> <a href="#" style="color:inherit;">RAL1001</a>

            <br><span class="color">D9BA8C</span>

        </div>
    </li>
    <li>
        <div class="box" style="background-color: #d6b075; color: #000000" onclick="setRalOption('1002','D6B075','0');return false;"> <a href="#" style="color:inherit;">RAL1002</a>

            <br><span class="color">D6B075</span>

        </div>
    </li>
    <li>
        <div class="box" style="background-color: #fca329; color: #000000" onclick="setRalOption('1003','FCA329','0');return false;"> <a href="#" style="color:inherit;">RAL1003</a>

            <br><span class="color">FCA329</span>

        </div>
    </li>
        </ul></div>

CSS

div.colorWrap { 
 display:none;   
}

JavaScript

$(document).ready(function(){
    $('#showColor').on('click', function(){
      $('div.colorWrap').slideToggle(); 
    });
});