The new design of the light card is great, but it would be nice to also be able to have an icon for the light temperature under the new slider instead of only the effect feature.
In the settings it would be nice to have check boxes to select which icon should be displayed under the slider.
Brightness 
Color
Temperature
Effect
It would be nice to include a switch which gives power to a smart bulb since when the smart bulb is deprived of any power (smart switch is in off state) the smart bulb is dumb.
If a selector field would allow to add/choose a switch entity, that always is switched on / off by clicking on the Lovelace light card, the smart bulb will stay smart because it gets power when someone clicks on the Lovelace light card and is therefore always accessible and adjustable.