To clarify further, most "watt-rated" LED products are rating the design limits of the "product", NOT the LED...
For instance, using a Cree LED, the EXACT same LED, in 3 different "model" flashlights, one might be a "1-watt", one a "3-watt", and one a "5-watt"... it's the same LED, but the driver circuitry (and/or power source) are modified.
Most LED mfgers rate LEDs at the following "current-points" in milli-Amps or Amps... 350mA, 700mA, and 1A. They release spec sheets that show the voltage curve as it crosses those typical points (some might add other points, for instance 500mA, and 1.5A, but the first 3 are VERY common.
An "old" white LED (2+ years ago model, or current "generic" models) might run at 3.2V@350mA = 1.12 watts (published as "1-watt" as mentioned by a previous poster, for marketing purposes). At 700mA, that LED might run at 3.6V = 2.52 watts (rounded up to "3-watts" for marketing purposes)... and at 1A, that LED might run at 3.8Vf = 3.8W= 4-watts approximately.
Fast-forward to today, a similar, but cutting-edge LED running at 350mA might be only 2.8Vf = 0.98W (1-watt again). At 700mA, it's running at 3.2Vf = 2.25 watts, and at 1A runs at 3.5Vf=3.5 watts.
That same LED today is electrically more efficient as you can see, it ALSO typically puts out MULTIPLE times more light at those same current points.
So wattage (consumed) is what mfgers typically list, but it's totally misleading, lumens or milli-watts output (used often for color LEDs) is the important visual rating, and the "light-output/power consumed" is your typical "efficiency" rating.
So an "old" white LED above running at 1A (3.8 watts) (consumed) might put out 140 lumens. A brand-new LED running at 1A (3.5 watts) puts out 280 lumens, so you get twice the light output, AND it runs longer as well (if on batteries for example, or uses less wall power, etc), even though both would probably be listed as "4-watts".
Finally, to answer your latest response, Cree and Luxeon (I don't know about Seoul Semiconductor) both make color LED varieties, and both are typically available at Future Electronics, Arrow Electronics, Cutter (cutter.com.au), or other large electronic supply houses.
I'd recommend reading a LOT more on this forum, and elsewhere, about LED tech though before buying anything, you have to consider soldering issues, thermal and physical design management, electrical circuit design, optical design, and many more subsets of all that, to really design anything useful around LEDs, as most power LEDs are "surface-mount" packages (can be hand-wired, with varying degrees of success and limitations) and are expected to be used with optics, diffusers, reflectors, or other optical modifiers.
