Did you know that you can generate nicely formatted HTML file from your source code with clang?
I just noticed this by peeking in the source code, took me a few attempts to get the command line right, but here it is:
clang -S -Xclang -emit-html test.c -o test.html
Which will create a colorful and nicely formatted version of your .c file, which you can see here.
The only annoyance? Not surprisingly, it will fail if the file syntax is invalid, or it can't be parsed correctly. You should probably pass all the same options as if you were compiling it for real.