WordPress' built-in editor has an HTML mode that lets you override the background color of a post by changing its CSS (Cascading Style Sheet) background-color attribute to the color of your choice.

Learn how to set the background color for selected text (instead of the entire document) in TextEdit ...

To change the background color, drag a color swatch from the color picker and drop it on the window. Repeat as necessary with varying colors until you have one you like.

You can change the background color in Google Docs First, it’s worth pointing out that you can actually change the background or page color in Google Docs directly from your phone.