Each & every element has its own characteristic emission and absorption spectra (which we all know). As the star traverses its main sequence stage - the hydrogen atoms are actually getting used up to form helium atoms. As it enters the red giant phase, helium starts to fuse by the triple-alpha process.
The Hertzsprung-Russel diagram gives the relationship between temperature and luminosity (Blue, yellow, red, etc.). As we take Wien's displacement law also into account, we could conclude that the spectra (emission or absorption) of the sol varies accordingly with its temperature. Now, the sun is at some 5000 K surface temperature, which gradually decreases to something around 3000 K. And hence, the spectral shift from yellow towards red. But, that may take about 3 or 4 billion years.
Oh.. You asked for 10 million years. In that case too, the answer remains the same. It's on its own way, hanging its spectrum because its getting old..!