There are several options for this, and the easiest are a new device form factor which has just started to come out, this is a smart switch cover. It fits over your existing switch and it has its own buttons. You leave the original switch powered on, and then use the buttons on the cover.
These devices can be used as a “button controller” with SmartThings, just like a minimote. The smart switch cover sends a message to the hub when one of its buttons is pressed, and the hub then send the appropriate message to whatever device you want to control with it. Which could include LIFX bulbs. 
Both linear and Osram have come out with versions of this. The linear Is zwave and the Osram is zigbee, but again it doesn’t matter. The switch cover talks to the hub.
So this gives you an intuitive switch on the wall, while keeping the smart Bulbs powered on. 
