Hello Helen, If I remember rightly you are a teacher and if you are marking your students work you probably make the corrections in red ink or with a red pen. It means the same in this context! Hope this helps Bob

Yes - a 'red pen' usually means a pen with red ink. In general, we refer to a pen by the colour of the ink, not the colour of the barrel. Usually manufacturers avoid confusion by making the barrel the same colour. So - we usually make corrections with a 'red pen'. If I asked someone for a black pen, I would expect to be given one that writes in black ink. In that case, it would be a joke to give someone a pen with (say) a black casing, and red ink.

In this case, we probably wouldn't use 'colored' of (dark) blue, because you normally write with a dark blue or black pen. These are the ordinary colors that don't need comment, and writing in just one of them isn't 'colored'. Anything else - red, green, silver, pale blue - would be called colored. When we talk about a red pen, a black biro, and so on, the color almost always means the color of the ink. If you needed to describe the plastic 'barrel' of the pen, you'd need to say so in more words: a red pen with a yellow barrel is a common type, for example.