I invite you to visit my website; though I don't have a design wall, if you put your "candidate" fabrics in the shopping cart, when you view the cart you will see them all on the same page, which is helpful.
We also show you coordinating fabrics - and these are selected by actually putting the fabrics next to each other and seeing if they work well together, not just in terms of color, but also having compatible visual "texture".
I would really be cautious using a color picker, or any other automated tool. The human eye responds to color and design differently than a computer does.