Dancing around another long spam series post by Marosz.
Paul, I am having trouble with your English, it could mean several things to me so let me try and phrase what the graph shows.
The graph is the wavelength along the bottom x axis and the power/energy density on the y axis in layman terms how bright that wavelength of color is seen (assuming we are in the visible spectrum).
So lets turn this into kinetic energy (motion of your molecules) with temperature.
So at 3000K most of your molecules contain an energy which equates to energy of a photon at 1um wavelength. Some are higher some are lower but the most are at 1um, not every molecule has exactly the same temperature. So the graph shows the spectrum intensity you would expect if the sun was at 3000K in temperature.
Similarly the 5000K shows the intensity for each wavelength you would expect to measure in a sun at that temperature.
The reason for the sharp cutoff to the left is you need a lot of kinetic energy in a single molecule to release those wavelengths which are way up in the ultra violent and heading up to x-rays. You don't have any molecules with enough kinetic energy to do that at these low temperatures.
If you want to have more energy to the left you need a hotter temperature you need 7000K to get up into the mid blues.
Let me see if I can get a color reference for you ... ok got one from an LED light manufacturer which is quite good.
Basically the hotter the temperature of your sun or light element the more left on that graph your cutoff will be.
Lets add a hotter sun on the graph the blue one here is 15000K it also adds the radiation of a human body. You can do this for any body at a temperature in a lab and measure the spectrum
It all conforms to Plancks formula which is why everyone uses it in all sorts of industries.
Most engineers and all physics graduates will have done labs and learn the trick because it is widely used for contactless temperature measurement. You also need to take care if you aren't dealing with an emission but you are sending in a EM beam to create a reading off a surface as the surface emissivity has an effect and so you need graduates to know that.
Hopefully AR2 will deal with Marosz and we won't be dodging in and out of the wall of spam.
