Since they aren’t colorblind, you don’t need to. Check out bilbrlsn’s reply to david_42’s comment below. There are also specially filtered images available on the web that will show you what a dog sees compared to what a human would see.
It’s called a typographical error, or “typo” for short. One that spellcheck wouldn’t catch. Look on your keyboard. Note that the “T” is adjacent to the “R.” Even professionals do it. Lighten up.
October 13 is also International Plain Language Day.