Nothing wrong at all but the kids who have taken a lot of trouble producing their presentation really hate it being defaced in red.
As I said, exams no problem, but essays and other projects are better marked in a less conspicuous colour. Especially for the girls.
For my design and technology students I always gave them feed back on a separate marking sheet that allowed me to give marks for originality, research, development of their idea, use of computers, their finished product and their personal evaluation of the product. By doing this I could get through to them much more readily than if I just wrote all over their work, in whatever colour.
Teaching is as much about psychology as it is about imparting skills and knowledge. You have to reach the students, and having reached them, you must not switch them off if you can help it.