This is completely incorrect when it comes to leds. 4500k is the tag it is given. In the overall sense, that number is meaningless. Evergrow's 4500K, and Sosci's 4500k are completely different leds, despite both being "Bridgelux 4500k".
The actual spectrum output of the led is much more important. The 4500k led that evergrow/reefbreeders uses is actually very good, and more closely mimics a 10k MH bulb in spectrum output, NOT a 4500k MH. Combined in a 2:1 rb to white ratio, the color is a very appealing 16-18k, and a wide range of spectrum is provided, along with adding 410-430nm violet leds, and a few 660nm red. I know this because I have it over my tank.
It also does not grow algae any quicker than a MH bulb would in a tank with correct parameters.