Rundown: ed

Highlight ed like a rainbow

1ed ${file} | lolcat

Use ed with command history

1rlwrap ed ${file}

Use ed with syntax highlighting

1type=sh
2ed ${file}.${type} | pygmentize -s -l ${type}

You need to specify the file's syntax type, because pygmentize -s reads the file one line at a time from the pipe's input.