I use Creative Grids exclusively as the Black/White line are the easiest to see for me. I'm a bit older and all those colored lines are never bold enough to really see. The ones with all those yellow lines etc make my eyes hurt and I never get a good cut. Creative Grids are a bit more in cost sometimes, but they last a long time and are thick enough that they don't nick easily.

Have you tried a Missouri Star ruler? Theirs are a clear neon yellowish-green and the markings are etched instead of in color and VERY easy to read thru. There are no lines of any color and I can see the markings well on any color fabric. I have the 5"x15" and the 2.5"x8" and these are BY FAR my favorite rulers. I make most cuts with them. If I have to cut longer than 15, I pull out my Fiskars one I got with my first cutting kit, but otherwise try to fold the fabric to be able to use one of these 2. If they ever come out with a 24" one, I will be the first in line! I don't think you would regret giving one a try before spending much on ones with colored markings.