Go to your local auto body supply shop (the one that provides paint to body shops). Bring a side panel. They will use a machine to scan the color. This can be used to find the best match. They can mix up the precise color and give it to you in a spray can.
...or, you can decide that going all matchy matchy with the color is the wrong idea. My design professional neighbor told me that matching the paint color on the bags only disrupts the lines of the bike and makes it look like it has a fat ass. She has a point. I had a pearl white EV and painted my panels a metallic black. These panels will scratch if you look at them the wrong way (they stick out and are the first thing to rub against something). I chose an off the shelf color so I could do quicky touch ups when (inevitably) I needed to repaint.
