chroma
Chroma is a general-purpose syntax highlighting library and corresponding command, for Go.
TLDR
Highlight a source file with python lexer and output to terminal
$ chroma --lexer="[python]" [source_file]
Highlight a source file with Go lexer and output to a HTML file
$ chroma --lexer="[go]" --formatter="[html]" [source_file] > [html_file]
Highlight a source file with C++ lexer and output to an SVG image, using the Monokai style
$ chroma --lexer="[c++]" --formatter="[svg]" --syle="[monokai]" [source_file] > [svg_file]