You may improve your score by noting that according to Wien's Law the peak location varies as 1/T, where T is the temperature, but area under the curve varies more rapidly-as the 4th power of T, according to the Steffan- Boltzmann Law. Thus, increasing T a moderate amount leads to a small shift of the peak to shorter wavelengths, but the area under the curve (and thus the height) increases much more dramatically.

The plot is always normalized so that the peak of the unknown curve is equal to unity. Thus, the guess will give a plot that is offscale if the guessed temperature is too high. When any part of the guessed-temperature plot is offscale an offscale flag is displayed. This is an indication that the guessed temperature is (perhaps substantially) too high.