I have never heard of 4K paint before. Only 1K and 2K. All of the numbers denotes the mixing parts to create a paint. And i could not find what 4K consists of.

Also when you buy off the shelf can spray paint of any brand all are 1K. Except some that says it is 2K. The local 2K can spray paint involves breaking an internal seal in the can to release the second part to mix the first part to create 2K paint. And the can contents only last 4 hours to use or it gets cured inside the can.