How do I add a background color to a text box?

Hello, I do not know if this question has been asked but I would like to add a background color to just a text box. I have text over an image and I would like to put a light gray or semi-transparent background under some text so it is easier to read. I have attached a image for what I am trying to achieve.

Can you share link to page where you added a text? We can give the code to achieve this.

Yes the website is here the password is " help ". The text in question is "Text Goes Here" on the home page. 

Thank you very much! That worked like a charm!