Colour Box Behind Headings

I have attached a snap from other site
How to add colorful box behind every headings as shown in snap.
Please guide

Hi @tipcircle,

I hope you are well today and thank you for your question.

Could you please share me the page URL from your site where the headings are displaying so that i can help you style it?

Kind Regards,
All the heading on this post and later on for whatever post i write

You can try achieving this by adding the following CSS code in the Custom CSS option of the latest version of Sparkling theme on the below path.

Admin Area -> Appearance -> Customize -> Sparkling Options -> Other -> Custom CSS

.entry-content h1, .entry-content h2, .entry-content h3, .entry-content h4, .entry-content h5, .entry-content h6 {
    background: #4395C7;
    color: #fff;
    padding: 10px;
    border-left: 50px solid #4D474A;