When preparing slides with a lot of code inside having a proper syntax highlighter is mandatory, and hacks like taking screenshots don’t work both for the useless amount of bytes wasted and for the inability to correct mistakes later on.
You can install highlight via Brew:
brew install highlight
highlight -O rtf input_file.php | pbcopy
pbcopy is a supercool utility that grab the standard input and copies it into the clipboard (yes, there’s pbpaste too).