The default formatting for many of the Styles in Word are, to be polite, less than useful. In a blank Word document the Heading 1 style is set to be Calibri Light, 16 point, and blue. Blue? Why did they choose that? Unfortunately, many people don't realize you can modify the Styles to look the way YOU want them to look.
You can change the appearance of a style, including its line spacing, font, color, alignment… just about anything! If you change a style, that change will affect all text in your document using that style. But those changes stay in just this document -- any new Word documents you create will have the default Word styles.