A basic code colorizer highlights language keywords, comments and string. A semantic highlighter performs full language parsing which results in very accurate understanding of code and may, for example, give local variables a distinct color to improve the comprehensibility of code.

Out of the box Visual Studio 2017 supports only user types highlighting:

SemanticColorizer extension by Andreas Reischuck can highlight local variables, class fields, parameters, properties etc.:

Codinion extension by Martin Topfstedt can highlight many more code elements, make text italic and bold, underline and overline text, set distinct font:

Codinion can also change background for code areas such as method body, region and preprocessor block:

Intelligent semantic code highlighting adds valuable information not available just from program text on the screen. Try it for yourself!