I also don't have an eye for color. Because of that, I tend to do shades of one color and that works well for me, or I have a few two color combinations that I like, like yellow and blue or turquoise and purple. I recently bought a layer cake and I was delighted that I was able to make a quilt that really looked right. But that is the same thing you are saying when you talk about the same fabric line.
I find that I don't like a lot of patterned fabric together, and that complicates fabric choice too.
However, I think the "design wall" in my head is starting to work. I can almost visualize what something might end up looking like. I do, however, always make a block of what I am thinking of before I cut out all my fabric. I learned that that helped the hard way.
I made a Warm and Natural pattern once that just looked awful. Didn't even finish it, just gave it to the guild and one of the ladies there made it into a useable quilt.
I have, however, learned to not fear selecting new fabric. I used to worry and worry, and now it is sort of fun. I guess that is progress.
Dina