Let's start with a soft white setting of around 2,700K -- the default for most smart bulbs including the three shown here: Philips Hue, Lifx, and Misfit Bolt (in that order). All three offer full white light spectrums, and all three do a good job at hitting those white light tones. Lifx is the brightest, Misfit Bolt the least so.
Here's a closeup of Misfit Bolt, with the camera exposure settings adjusted for that particular bulb. It isn't quite as dark as the shot with all three bulbs make it look, because that shot has to compensate for the brightness of the other two.
Now let's get to the colors. All three bulbs are able to produce vivid shades of red. Lifx is actually dialed down to 50 percent brightness -- anything higher starts adding in white diodes and giving you tinted light (pink, in this case). And again, Misfit Bolt is the dimmest.
Next up: blue. Misfit Bolt is even less bright here, and if you look close at the Philips Hue on the left, you'll see a faint indigo tone to the light. That's because its blue diodes aren't very powerful, forcing it to add in a little bit of red to put out enough light.
Three bulbs, three different takes on green. Lifx is clearly the closest to pure, vivid green here, while Philips Hue can't muster much more than tennis ball yellow (again, those blue diodes just aren't that powerful).