Absence of syntax highlighting in HTML code indicates a lack of visual differentiation among elements, attributes, and text. This often manifests as all code appearing in a single, uniform color, which reduces readability. For example, in an uncolored HTML document, tags like <div>, attributes like `class`, and text content would all be rendered in the same color, making it harder to quickly understand the structure and elements of the code. The specific reason code isn’t colored can be due to a multitude of factors, and each case should be addressed and fixed accordingly.
Appropriate syntax highlighting significantly enhances code comprehension and reduces the likelihood of errors. Color-coded code allows developers to quickly identify different code components, leading to faster debugging and more efficient code maintenance. Historically, text editors displayed code as plain text. The introduction of syntax highlighting marked a substantial improvement in developer productivity and code quality. This advancement streamlined the coding process.