How do you say blue pen in french?

There are a couple of ways to say "blue pen" in French, depending on the context:

* Un stylo bleu: This is the most common and literal translation, meaning "a blue pen."

* Un stylo de couleur bleue: This is a more formal way to say "a pen of blue color."

You can also use "un crayon bleu" if you're referring to a blue pencil.