You can configure text appearance in the Appearance tab of a text widget. Just set the Color option to ‘Brand Danger’, and the existing styling framework should do the rest.
Thank you for your response. I found that the color can be changed in the Color item in the Text Appearance. What I want to do is to add a new "Sample1" element to this Color item.
As Marius said use the default style options if you needed other than that write a separate class and add the color style as per the requirement color