Brooke, the major difference between the manuals and the autos is just how it's activated. THere is always a fraction of a second before the heating coil in the atomizer warms up and vaporizes the liquid. With autos that means a moment or so of air before the vapor starts. With manuals you can press the button while lifting it to your lips, so you get vapor as soon as you inhale.
ANd MMcall, Blue and red/orange are our most popular LED colors. We have ordered other colors but they have not been hot sellers. And some, like green and pink, have garnered a LOT of bad feedback.

So, blue and red/orange are what we've ordered lately, and what we're likely to order in the future.
That said, we've had a lot of requests for purple LEDs, so we've been trying to get those for a while, and just might sometime soon. But whether those stick around will depend on how they sell.