Piperine was chemically characterized by reaction with acids. This was done by dropping concentrated $\ce{HNO3},$ $\ce{HCl},$ and $\ce{H2SO4}$ to a sample of piperine. Both $\ce{HNO3}$ and $\ce{HCl}$ produced yellow solutions while sulfuric acid produced a blood-red solution.
What happens to piperine as it reacted with $\ce{H2SO4}$ and why it turned blood-red? Also, what is the difference of that reaction with the reaction of piperine with $\ce{HNO3}$ and $\ce{HCl}?$
Edit: Late addition for viewer's convenience:
The piperine structure is shown below: