Unstyled HTML appears as plain text within a web browser. This lack of visual distinction between elements like headings, paragraphs, and lists makes the code difficult to read and interpret within the browser window. For example, a level one heading will appear with the same font size and style as regular paragraph text, rendering the inherent structural hierarchy of the document invisible without inspecting the source code.
Applying colors and styling through CSS dramatically enhances code readability during development and debugging. Clearly differentiated elements allow developers to quickly visually identify structural components and spot errors in markup or styling. This visual clarity has been paramount since the early days of the web, evolving alongside CSS to provide ever more granular control over presentation and user experience. This visual feedback during development became crucial as web pages grew in complexity.
