I am reading Froala's online documentation here
https://www.froala.com/wysiwyg-editor/docs/options#colorsBackground
I am able to find the option called colorsBackground. However, in Froala's online examples, I am not able to find one showing a background button. I am able to find a button for text color, but not background color.
Just found it out. It is there. When you click the colors button, you have two options in the top: color for the text AND color for the background. It can be easily in my case because the tab for the text/background is so similar to my page's design.
It is there!