What kind of bag is it? You should suit the lining to the function of the bag.
If you're going to need to hunt around in it for things, choose a silver, gray, white, sky blue or other pale colored lining, because it's easier to see things on pale backgrounds. On the other hand, it shows dirt a lot faster; even if you tend to lose things on dark backgrounds, at least the dirt doesn't show as fast.
Otherwise, anything that's hardwearing and tightly woven, won't be harmed by keys, knitting needs, crochet hooks, cell phones, camera, etc. in the bag, and is -- oh yes -- decorative will work.
If it's a "whatever" bag, use whatever takes your fancy. If it's a bag that you really want to show off and showcase, then choose a bit more carefully.
There's a new magazine in the UK called The Knitter, kind of like a Threads for knitting. There's a beautiful cabled purse and tote project in tomato red alpaca that I'd love to make -- the designer used a Liberty print to line them...oooh, doesn't that sound lovely? And I'm so close to Liberty's...