The pen is blue circulates online as a short meme sound, shared on soundboards and in short-form videos rather than tied to a widely documented film or television scene. Its appeal is the blunt, frustrated delivery, which makes it easy to reuse whenever a creator wants to call out denial of something plainly visible. Because the line is short and self-contained, it works without context, and it has stayed in use as a reaction clip for arguments, debates and deliberately petty disagreements in memes and edits.