In directions it does say there is a spelling error.
But it also says to just ignore it and add the fall back value of black.
freeCodeCamp directions
Rather than fix the typo, add a fallback value of black to the background property of the .penguin-top and .penguin-bottom classes.
Probably what happened is that the team at the time decided to leave the typo in there and just acknowledge it in the directions so users know about it.