I've used a bunch of different ways. IMO the sports bag from the thrift store is a good idea. They usually have several back pack types of bags. I really liike the color coded idea. Hadn't thought of that one. I'm in the flat winder camp. They just work better for me. I use a lot of those orange electric cord winders, the flat ones, you get from the hardware store.
Now, all that being said, don't rule out the no winder approach. I sometimes just sew up a bag and stuff the line it. No winder. You'd be surprised, there a few if any tangles using this approach. I especially use this technique when traveling. It's easy to shove a no winder bag around to fit the space available in a duffle or other travel bag. I know it sounds like you'll end up with a mess but give it a try. You may be surprised.
The down side is that it does take longer to stuff the line into a bag at the end of the day than it does to wind it up on something.