Slight change to ArnoldPatch::updateLights.
Changed Juce App to show a demo with varying color. Minor changes on Device.

Current problem with the demo. The change on color doesn't "seem"
to be linear, though it is changed in the linear way. Tried both
lerp function and setRGB linearly. Device::getColor is changed to
use c-styled cast, since dynamic_cast returns NULL (needs a better
way to correct).