However - we want to show you one way that might be easier for you to select your own fabric and feel pretty confident that it will work.
One technique is called "grayscaling" the design. Simply put, you're just taking a picture of a finished pattern presented to you in color and "graying" it out (changing it to Black and White).
There are numerous ways to change a color picture to black and white and it depends on how tech savvy you are, but one simple way is to print the picture/pattern in black and white. When you grayscale, then you can see the actual color values of what you need to look for in terms of light, medium and dark.
This method does 2 things - first it shows you the color values of where it is light, medium and dark. Secondly by printing the pattern in black and white subdues the actual fabric print(s) used in the quilt that might prove distracting to you if seen in color. Meaning let's say a pattern uses floral for a large center block, but you'd like to use this really great geometric fabric print you saw, or maybe it's a dog, or... By printing the picture in black and white reduces some (not all) of the distinguishing characteristics. Additionally it may help to point out whether you need a fabric that might require more texture in one area and maybe not in another. For example see below.