Change color and more via costum css in Elementor

Hello
I want to change the color, size and style of a text (content) via css in the Elementor Page Builder in Wordpress.

Using the Costum css in Elementor , I wrote the following
εικόνα

The result is to see my text on a red background.
But I do not want that. I just want the text to change color and not the background

What do I need to write in the Costum css box to change?

If you want to change the text color, the CSS is color: red;

If I had chosen a simple text the above would work

selector{color:red}

but I have not added a plain text, but I see a title that emerged from the plugin 3d flipbook.
To take from the beginning:

  1. I have install the 3dflipbook plugin
    2)from this plugin i chose a pdf file from my library
    3)I choose to display only the title of the file on my page, for example “BOOK1”
    4)The plugin creates the Shortcode

[3d-flip-book mode=“link-lightbox” pdf=“https://sub.testpage1.cf/wp-content/uploads/2021/02/BOOK1.pdf”]BOOK1[/3d-flip-book]

  1. I enter the above Shortcode in the Elementor

6)To change the color of the title “ΒΟΟΚ1” , I have two options.

  • directly edit and change the aboveShortcode , that I do not want
  • edit in the Costum css in Elementor.

I have edit in the Costum css in Elementor

selector{color:red}

but nothing happened

What exactly should I enter to change the properties of the title “ΒΟΟΚ1” such as color?