Newbie here 
. I have 3 sections of cabinets (each with an outlet above) that I want to install under-cabinet lighting on without running an extension cable that would be visible (also two of the sections are on different sides of a vent hood chimney that goes all the way to the ceiling, so I can’t run an extension there). We just moved in and I’m comfortable with wiring, soldering, installation, but I’m brand new to the whole smart home/appliances/devices scene. Is there a way to control these 3 separate areas with one wall switch? The wall switch would have 110V AC, but wouldn’t be able to be wired directly to the light strips/controllers themselves. Can the color be controlled by the switch at all or would that have to be done via an app?
Do you have an extra space in a multi-gang switch box that isn’t used? You could link a smart switch to smart outlets via a rule. Another option is to get a remote or battery powered switch that sticks on the wall and do the same.
I don’t have a double gang box right now, but I can add one pretty easily. What smart switch and outlets would you recommend?
i’ve had good luck with GE and Zooz switches. Haven’t bought any in wall outlets, but people seem to like the GE ones. Also, i believe if you get all z-wave devices you can use a direct association between the switch and outlets so that a rule isn’t even needed in SmartThings.
As @Automated_House mentioned, any switch, including a battery operated switch, which communicates with the SmartThings hub can then be used to control any group of devices which are also controlled by the smartthings hub. The switch send a message to the hub, the hub sends a message to as many different outlets as you told it to. So that part is easy. 
You still need one device per outlet to let the outlet itself talk to the smartthings hub. If these are regular 110V outlets, you will have a lot of choices for on/off. If they are specially made for LED strips and are 12-24 V you’ll still have a few options.
To change the color, most people would either mount a small WiFi phone that had a color dial on it or is a multi button switch to let you change to different preset scenes. There’s one popular battery operated device which has eight buttons each of which can do tap, double tap or long hold, giving you 24 scenes for one light switch size device, but there are a lot of other choices as well.
This first link is the list of all the button devices. This includes both battery operated and mains powered and both handheld and wall mount so read the descriptions carefully. But you’ll see there are a lot of choices.
As far as 110 v outlet choices, US code requirements mean they all end up being very similar with the exception that older models generally only have one of the two sockets which is controllable from the network and as of 2017 we are starting to see a few models come out which can control both sockets.
Awesome, thank you! 