Remove an HTML tag from Div [closed]

I use a WYSIWYG editor in my website. It has the option of changing the font-size and fontcolor of the chapter.

However, I want to make sure that if the user desires, they can actually override the font settings while reading it.

I know I can just get the innerHTML and replace the font-size and color attributes from it. However, it may be possible that font-size and color may actually be part of the text instead of HTML tag.

So how can I remove these attributes from HTML without affecting the main text?