Can you change the color of customizable text?

Yep so adding CSS is what you have to do if you want to change the color and style of words. The Customised Text section is just for changing the content of the text itself, not its style.

Instead of adding CSS directly to the default theme though, Discourse has theme components which allows you to add CSS on top of an existing theme.

Just to be clear about expectations, Meta is not a dedicated support site for a complete guide to getting started with CSS (just like it is not a dedicated support site for learning Ruby and JavaScript completely from scratch, if you wanted to start customising the behaviour of Discourse through plugins). If you want to customise the appearance of Discourse, you will need to learn more about CSS.

So there are guides on making theme components and plugins for Discourse here, but not for learning CSS or Ruby from scratch (since that’s a general skill). Sometimes people have time to kindly help, but it’s not always going to be possible, because it means having to go through general HTML & CSS knowledge – the basics of the Inspector and classes and properties etc.

Here is an intro guide to making CSS changes on your site: