Color me yellow: Poly(ADP‐ribose) polymerases (PARPs) play a major role in cellular survival and maintenance of energy stores after genotoxic insult. The colorimetric PARP substrate ADP‐ribose‐pNP can be used to monitor PARP activity. By monitoring the production of p‐nitrophenolate, the kinetic parameters of PARP‐1, tankyrase, and PARP‐4 could be evaluated. ADP=adenosine diphosphate, pNP=p‐nitrophenoxy.