The Pilot Hi-Tec-C Grape is an ink color I have come around on. At first, I felt it was too light for normal everyday use on things like work notes and lists, but the more I used it, the more I found it complimentary to other colors on the page. Aside from drawing or sketching - which I don't do a lot of - this is what I use most of the non-basic colors for. I'll make the majority of my notes and lists in a dark color such as black or purple, and then use a lighter color to mark up the list, scratch things off, and add any type of detailed notes. If you follow me on Twitter and see my somewhat daily pen log, you will notice that I often mention two pens I am using, and it is for this exact reason.
I wish the photo came out a bit better on this one, but I think you get the gist of the ink color. Plus, this was some of the cleanest writing I have done if I do say so myself!