Alternative way to handle CWWW led bulb

**Describe the problem you have/What new integration you would like**

I bought couple of "SL06" cold white/warm white led bulb, instead of having 2 parallel channels for cold and warm they put them in serial, from electronic point of view one mosfet transistor is connected to both warm led and to second mosfet transistor controlling cold led. It's impossible to light cold led alone, it's impossible to bright cold led more than warm led. To resume, there is a PWM channel for overall brightness and a second PWM channel too "cool down" the light temperature.

**Please describe your use case for this integration and alternatives you've tried:**

Actual workaround is to declare the cwww light bulb as a RGB light bulb with the following setup:
red channel for PWM1 (the overall brightness)
green channel for PWM2 (the cold led)
blue channel to dummy pin (not wired)

When setting the light color to 100% red, 0% green, 0%blue I have the warmest possible color.
By adding green without changing red I'm cooling down the light.
The brightness control work fine in this case.

**Additional context**

No repository file, test, or entry point is mentioned. Start by locating the CWWW light integration and its PWM/RGB handling, then compare the requested serial LED behavior with the existing workaround. Done means an agreed alternative representation that controls brightness and color temperature correctly, with coverage for this bulb configuration.

Written by the indexing model from the issue text.