How to assign a value to a variable and use it to change colors?

Question

Web development

How can I create some variable which is set to "some hash color". Then you need to use this variable, for example, to change the color of the main menu on the site or some forms, widgets. Like a color scheme for the entire site. I would like to change the lighting scheme of the entire site every day, for example, but in order not to poke around in all the files, I could change just one variable and thereby change everything. And how can this be applied in WordPress?
PS CMS - WordPress

Answer 1

You need to use Sass. How to use it in WordPress - tons of articles on google.