Take this picture and open in and blow it up and look at Ivanka's black book and pen.
Sure looks like Q's post with the watch.
That could be the angle and lighting that makes it look blue, plus anybody that can play with pictures could make it black in a heart beat. Just a possible link to the pic that Q posted.
Potus' pen looks maroon in that pic. Ivanka's is a closer match to Q's pic.