Fairly often I get the request to update all instances of a color on a site to a different color

For example:

*Across the entire website, for any element that it currently #51284F (text, buttons, etc,) please update the color to #4F9CEC*

Of course, this would normally be done with CSS in the style sheet. However, this is a very large website with hundreds of pages, and we aren't sure exactly which elements are currently set to #51284F, and which pages might contain an element that is set to #51284F. Additionally, this request comes up often, so it would be helpful to have an efficient way to change all the colors at once as opposed to manually going through each page and writing CSS for every element that needs a color update.

So, using JavaScript, is there any way to search the entire website for any element that is currently set to #51284F and update its color to #4F9CEC?

The HTML would look something like this:

```
<div class="header-default" data-widget-name="header-default" data-widget-id="template-header1">
    <ul class="tels">
        <li class="tel phone1 collapsed-show" data-click-to-call="Sales">
            <span class="type">Sales</span>
            <span class="separator">:</span>                                    
            <span class="value">123-456-7890</span>
        </li>
        <li class="tel phone2 " data-click-to-call="Service/Parts">
            <span class="type">Service/Parts</span>
            <span class="separator">:</span>
            <span class="value">123-456-7890</span>
        </li>
        <li class="tel phone3 " data-click-to-call="Body Shop">
            <span class="type">Body Shop</span>
            <span class="separator">:</span>    
            <span class="value">123-456-7890</span>
        </li>
        <li class="tel phone4 " data-click-to-call="Local">
            <span class="type">Local</span>
            <span class="separator">:</span>                            
            <span class="value">123-456-7890</span>
        </li>
    </ul>
</div>

```

The CSS would look like this:

```
.header-default .tels { color: #51284F; }

```

Unfortunately, these are template sites, so we don't edit the HTML on a site-by-site basis. The HTML itself pulls from the particular template that the site is on

Thank you so much!