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Most white LEDs are really blue LEDs covered with a layer of mixed phosphors. They can pick any phosphors they want to set the color temperature. You can buy much more expensive red-green-blue LEDs and control each color separately to get any color you want. But that's just human perception: Those have very narrow bands of red, green, and blue with nothing in between. Put a yellow, cyan, or magenta object under those RGB LEDs and it looks black! That's why they have a very low Color Rendering Index.
The much stronger and cheaper white LEDs phosphors have broad spectra of emission, so they can get 90% or even higher CRI. (Sunlight is 100%.) And any white LED has enough of every color that you can put gels in front of them to alter the color temperature.
Fun stuff! The other fun thing is the brightness is controlled by current. The voltage does not change much since they are semiconductor devices, actually diodes. So you have to run them with a current regulated driver, and vary the current if you want to dim them. Takes some commercial drivers or knowing what you are doing if you want to DIY. A lot more complicated than an incandescent bulb. About half the cost of an LED fixture is the driver.
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