javascript - 无法在 materialize.css 中使用 javascript 更改按钮颜色

Question

我是 materialize.css 的新手，实际上我想使用 javascript 在点击时更改按钮颜色。单击的每个按钮都必须根据按钮内容产生不同的颜色。但是当我点击他的按钮时，它并没有改变它的颜色。

  <div class=" buttons  row center-align">
<button class="btn col s12 m6 deep-purple darken-4 center-align" id='button0'  onclick ="answer('0')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option0"></span></button><br>  
<button class="btn col s12 m6 deep-purple darken-4 center-align" id='button1'  onclick ="answer('1')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option1"></span></button><br>
<button class="btn col s12 m6 deep-purple darken-4 center-align" id='button2'  onclick ="answer('2')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option2"></span></button><br>
<button class="btn col s12 m6 deep-purple darken-4 center-align" id='button3'  onclick ="answer('3')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option3"></span></button><br>
 </div>

JavaScript

 function answer(ans){
  var z = document.getElementById('option'+ans);
  var choice = z.innerHTML;
  var b = document.getElementById('button'+ans);
     if(choice == questions[x].answer){
       b.style.backgroundColor = '#008000'; 
       b.style.color = 'rgb(255, 255, 255)';}
     else{
       b.style.backgroundColor = '#700000';
       b.style.color = 'rgb(255, 255, 255)';}

Answer 1

html

<div class=" buttons  row center-align">
<button class="button col s12 m6  center-align" id='button0'  onclick ="answer('0')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option0"></span></button><br>  
<button class="button col s12 m6  center-align" id='button1'  onclick ="answer('1')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option1"></span></button><br>
<button class="button col s12 m6  center-align" id='button2'  onclick ="answer('2')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option2"></span></button><br>
<button class="button col s12 m6  center-align" id='button3'  onclick ="answer('3')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option3"></span></button><br>

只需删除 materializecss 按钮类 'btn' 并替换为任何名称，我用按钮做了并删除了按钮标签内的 materializecss 颜色类，所以最后每个按钮都是类:

 'button col s12 m6  center-align' 

并在为此 html 文件自行创建的 css 文件中；(main.css)

.button.col.s12.m6.center-align{
   background-color: #311b92;
padding: 10px 20px 10px;
border-radius: 50px;
font-size: 2em;}

现在，当我们应用问题中提到的上述 javascript 方法时；点击按钮颜色会改变