I haven't tried using Alexa but I got most everything working I wanted by using Vera and Control4. Since my lights are all z-wave, that is why I have Vera. I've tried the Control4 z-wave controller and it just doesn't support many devices. So, Vera has a plugin to manage Magic Home. It is written in Lua, so my thoughts are that it may be able to be reused for Control4 drivers. This is outside of my expertise. msgreenf mentioned he is working on a driver.
I am able to manage everything through Vera including dimming, changing colors, setting modes, etc... First create a scene in Vera for colors and modes. Then from Control4 I created the led strip light as a dimmer. After that, create and map the Scenes in Control4 for the different colors and modes. I can now turn the light on, change the colors through the scenes, and also control dimming of the lights. So far it works how I want it to work. If I want to change to a different color, that isn't defined as a Scene, or turn on a different mode (rarely used) I'll just use the Magic Home app.