I can give you a conceptual answer and you can write it in the proper syntax in the tool.
You can define a white light of uniform spectral radiation intensity by S(lambda) in watt/ cm^2/ wavelength interval dlambda over the whole bandwidth from 0.3 to 0,8 um. Assuming the total light intensity p is equal to 100 mw/cm^2 for one sun, then S= 100/ 0.5 um= 200 w/cm^2/ dlambda um.
White light can be also synthesized from three light color components red, green and blue in a specific proportion. It can be constructed also from the complementary colors such as the yellow and the blue.