So there are several factors here.
The first is the command being sent to the bulb from whatever app. You can improve your odds by sending the bulb a command that includes level and CT, as opposed to just "on" and then adjusting those values. Sending a bulb a non-zero level implicitly turns it on. You can play with what the device itself does by sending it commands directly from the device page. (As an aside, none of my bulbs go directly to the desired CT when commanded, somewhat to my annoyance. They turn on at the last-used CT and transition a fraction of a second later. I live with it.)
Next is getting that command sent from the activation device. If your switches are Scene Controllers, you can set the behavior of the button to send that command; that's one of the screenshots I had earlier.
[PRERELEASE] Virtual Prestaging catches anything that falls through the cracks, plus maintains it over time. When a target light turns on, it gets sent the CT value from its source and immediately sends the CT command to the newly-activated light. It also sends commands to all the target lights that are on if the source changes.
