JSFiddle - React, Tailwind, and code Playground

HTML

<select  onchange="updateColor(this.value);"  name="sunday combo" id="Suncombo2">
    <option value= " " selected="selected">Please Select</option>
    <option value="FFFFCC">light yellow</option>
    <option value="CCFFFF">light blue</option>
    <option value="CCFFCC">light green</option>
    <option value="CCCCCC">gray</option>
    <option value="FFFFFF">white</option>
</select>
 
<table>
 <tr class="5row">
<td id="2ndInputMon"><textarea></textarea></td>
<td id="2ndInputTues"><textarea></textarea></td>
<td id="2ndInputWed"><textarea></textarea></td>
<td id="2ndInputThurs"><textarea></textarea></td>
<td id="2ndInputFri"><textarea></textarea></td>
<td id="2ndInputSat"><textarea></textarea></td>
<td id="2ndInputSun"><textarea></textarea></td>   
</tr>
</table>

JavaScript

function updateColor(color){
 myCell = document.getElementById('2ndInputSun');     
        myCell.firstChild.style.backgroundColor = "#"+color;

}