Lets see how this works
Let's look at a few lines from my terminal as an example.
Here is what they look like if I simply indent the block of text without any code fence or anything.
~/Sites/d7sandbox1/sites/all/themes $ rm -R mybrokentheme
~/Sites/d7sandbox1/sites/all/themes $ drush vset -y theme_default bartik
Sweet. No syntax coloring. This is how it should be.