[somebodynew]

> To begin with, all modern LEDs are blue, if you see a white LED, it's a blue LED, if you see a red LED, it's a blue LED.

It is true that "white" LEDs are really blue or violet LEDs coated with phosphors that glow white or yellow (RGB LEDS with independently controlled red, green and blue LEDs are rare and only used in things like color-changing light bulbs).

It is not true that "if you see a red LED, it's a blue LED". Red LEDs are still made with semiconductors that directly emit red light (and the same goes for green, etc.). You can look at the spec sheets for LEDs on a distributor like Mouser and see the material used for each LED. The first red LED I came across directly emits red light using AlInGaP. I have never seen a "red LED" that uses a blue LED to excite a red phosphor. That would be even more expensive.

[RL_Quine]

Surprisingly, they actually are blue dies with red phosphor. Keeping all the colours the same forward voltage makes driving them a lot easier, as well as having all the colours in the same production process.

[somebodynew]

It seems conceivable that a red LED based on phosphor excitation could exist somewhere where having the same forward voltage for different colors was essential, but I haven't been able to find one.

Taking into account the different forward voltages for different LED colors is a standard part of designing an LED circuit. One of the LED data sheets I have on hand for some 5 mm LEDs includes a forward voltage chart with 1.9 V for red and 3.2 V for blue.

Do you have a part number for a red LED that operates by illuminating a red phosphor with a blue LED?