Cleanup: f_color, fl_color, and related

Cleanup: f_color, fl_color, and related

In particular, some of the color print functions are not following the naming convention.
The function fl_print_color() should instead be fl_color_print().

Make sure appropriate #define statements have macro in their name.

Add some @fixme comments because f_dynamic_string is designed with the intentions of not being NULL terminated.
Directly using it with standard functions like fprint is dangerous.