To remove direct formatting and keep your present formatting, you must apply styles instead. You’d use mainly paragraph and character styles. Styles are a collection of attributes to apply to an "object (here paragraph or word(s)). So, formatting is defined only once under some name and applied multiple times. Configuration is stored only once, contrary to direct formatting where the attributes are stored at every occurrence.
If you’re new to styles, read first the Writer Guide to get an idea about what they are and how you use them. Then think about what you need in your document. Consider your paragraphs can be grouped in broad “semantic” categories like headings, main discourse, comments, notes, examples, … Each category corresponds to one paragraph style (so that you ensure formatting consistency all over the document. Several built-in styles are intended for very common categories: Heading 1 to 10 for 10 levels of heading, Body Text for the main discourse, Footnote for, guess what?, footnotes. You can define as many custom styles as you need, but don’t exaggerate: usual documents never require rarely that 10 custom styles in addition to built-ins.
The same can be said for character styles: most used built-ins are Emphasis and Strong Emphasis (translated as italic and bold respectively). Here again, if you feel like creating more than 10 custom styles, think again about how you decompose your document.
There are also page styles but, apart from First Page (cover page) and Default Page Style, you must create your own layouts if you have a lot of differing “parts” with their own look, like legalese, TOC, Index or appendices.
Built-ins are not “locked”. You can customise them to fulfil your taste.
You should notice that none of the names I mention describe the visual look of styles. You suggest the intent or “significance” of the “object” (paragraph, word or page). This is called semantic styling and is far better that the “naive” approach of naming “Blue paragraph”. Take the example of italic which is used both for emphasis and foreign words. If your style is “Italic”, you can’t format separately important words and foreign words. Use different styles for different significances: in this case built-in Emphasis and to-be-created custom Foreign Word (and in the latter you can set language to None in order to silence spellcheck).
