The fact that bulbs are 1. small and 2. run on mains electricity is a big complicating factor. By far the easiest way to build this would be with dual-colour LED strips. But that's not how most people want to light their homes.
What is hard about these?
For a few dollars I can convert 120v to whatever I want.
Sell a different version to Europe
A solid driver with good filtering and good thermal characteristics is expensive. So you're left with a $15 LED bulb that sits on a shelf next to $5 bulbs, selling to customers who see nothing other than two LED bulbs where one is grossly overpriced for no reason they can comprehend
The fact that this hardware runs at 120v (or 240v in my case) makes it the barrier higher as there's now a chance that making mistakes might kill me.
Additionally, the high power levels mean that adequate cooling is needed, and as a non-expert it's hard for me to know whether I've done that correctly.