Sounds like the dry burn didn't get all the gunk and it's still burning away in there, or, you may also be holding the button down a bit to long when inhaling vapor, causing the heat to build up and darken the juice. Some darkening is normal as the juice steeps quickly with the addition of heat, (think of tea, how it darkens in hot water), but holding the button down to long or too frequently may overheat the fluid.
When we first start out it is easy to go through a few atomizers trying to get the hang of it all, I would re clean it, and try again, experience is the best teacher and don't feel bad if you ruin an atty or two getting it right, you will with time!
Are you by chance using a variable voltage battery? (Either the twist or the new eGo's that can be set to variable voltage, (yellow light) or regualr voltage, (light blue light)? If you are seeing a yellow light, click five times fast, (to shut off), hold down button for five seconds, until light blue light comes on and flashes, then five clicks to turn it back on. It should now light up light blue when pressing the button and should not burn your juice as easily.
Try these things and let us know what happens!
Good luck!
