Black and dark blue ink are the standards for general writing. Countless forms have instructions saying to use black or dark blue pens only, and other ink colors seem a bit showy for writing whole letters. However, when you need to write additional notes or create signs that people will see for sure, black and dark blue can be nearly invisible, in a way, because people are so used to seeing those colors. They don't stand out enough to be distinguished from any other signs or text nearby. If you want to have people notice what you write and have it stand out from black or blue text, you need to use other colors. But the color you choose could also create issues if you use it in the wrong context.
Red Equals Alarm
You'd think that red ink would be perfect if you want to get people to notice your written comments; it's the classic editor's color, right? Not quite. Red signals alarm or urgency, and the sight of a page of text festooned in red ink strikes fear in even the most confident of writers. Now imagine how your office's new college intern would take seeing a page marked up in red by a supervisor. Not good.
Red is still used in last-stage, paper-based proofreading (most editing and proofreading tasks are done on computers now, but a few projects still have a paper component) because in proofreading, you absolutely need whoever is making the corrections to see every last note. In other words, there is actually a low level of alarm associated with that last stage in publishing corrections. But for notes on projects and other writings that aren't urgent, red is usually inappropriate. It is too "scary" for general notes.
Pastels Can Be Hard to Read
So how about some nice, soft pastels, like lavender or light blue? Those, unfortunately, can be hard to read, especially if the writing is small. While some pastels do stand out on white paper, they are not as distinct as darker or brighter colors.
Blue Can Blend Too Much
At this point, a medium blue sounds good; it's not as alarming as red or as mainstream as dark blue. However, it can still blend in too much with dark blue or black ink. It's better than nothing, for sure, and better than a pastel color that's too light to read easily. But it's not optimal.
Rich Greens and Purples Are Easy on the Eyes
So what works, then? Rich green and purple (darker shades, not lavender) are perfect. They stand out among black and blue text, do not raise the alarm like red, and are easy on the eyes. It's fairly simple to scan a page for notes when you know you have to look for green or purple ink.
Find a pen in one of those colors that glides along the page and doesn't skip spots of ink. Look for finer points as those will allow you to write smaller notes without losing legibility.
For more information, contact a company like Flax Pen To Paper.