plus a phosphorus layer on top that smooths those two perfect lightwave color peaks in the wavelength domain into a broader light spectrum

The phosphor absorbs some of the blue and downconverts it to green and red. Some of the blue is let through for us to see. The mixture of R, G and B looks like white to us (but not necessarily to other animals with different cones in their eyes).

2 kinds of light emiting diode (LED) junctions inside - red and blue

I've never seen a red LED die inside a white LED. I've only ever seen blue dies on their own.

Technically UV-pumped white LEDs exist, but they're rare and I've never seen one. They're less efficient and require a third phosphor (to make the blue).

You can remove the yellowish looking phosphors on the LED with a small pick to reveal the blue die underneath. Fun fact: some high-power "red" LEDs are actually blue leds + phosphors, not that it's a particularly good choice but it's a thing: https://halestrom.net/darksleep/blog/018_led_cob_cutting/