You still have to comply with Building Codes
The Building Codes are crystal clear: There must be a physical switch, in a quasi-standard location (you can walk into any room anywhere and your hand knows the 2-3 places to grope for a switch). The switch must be accessible by people who aren't you, and the switch must operate a light that works. That includes guests and first responders.
Of late, the recent trend is for people to get so excited about these smart dingbats that they forget to make their house accessible to anyone else. You can do that to your heart's content with auxiliary lighting; and you can make this auxiliary lighting your personal primary lighting. However the actual primary light - the one on the obvious switch - has to work everytime. Not turn it on and find somebody's set it to 5% brightness on their phone.
Nothing says you need to use this primary lighting, ever; in my family we never use it. As long as the primary light works for a visitor.
I'm sure you've also gone into restaurant bathrooms to find the room pitch black, and to find some sort of smart device on the wall that you have to futz with, typically a defunct motion sensor with a hard on/off button as backup. That's another example of what not to do.
In the family
So, this narrows you to combinations of smart bulbs and smart switches that are "in the family": that can talk to each other. The smart switch needs to be able to override whatever you did with your phone, and make the light white and bright based on ignorant groping by an inexperienced user with gloved hand, as you would expect from a fireman trying to see if the room is evacuated.
Now, obviously there's a stupid way to hook up a smart switch with a smart bulb. If the smart switch severs power to the smart bulb, then the bulb becomes uncontrollable because it has no power. Only one device can actually control a bulb; all other devices must ask its permission. This is why the switch needs to be able to talk to the bulb. You might rewire the switch so the bulb is on 24x7 and the switch taps the power it needs to be online.