Wavelegth requirements for photosynthesis

[Sorine]

Hello everyone, first post after a great deal of lurking and reading.

I am hoping someone might know what wavelengths of light are needed for most plants for photosynthesis. I want to build a LED fixture based on Luxeon Star LEDs. I can get a cool white LED that will produce light at 5500 and 6500K but since it's an LED the wavelength is very narrow (and from my understanding K is not a relavent measurement even for a white LED). I will have to make an array of numerous colored LEDs to get all of the required wavelengths.

The cool white LED I'm considering using as the primarylight source is:
http://www.luxeonstar.com/endor-rebe...00ma-p-179.php
The other colors of the same style are here:
http://www.luxeonstar.com/luxeon-rebels-c-28.php