Reflectance from IE solver in HFSS

I am working on a scattering problem in HFSS and would like to plot the Reflectance vs. Frequency for my object. My object is on the order of a few um and I'd like to plot reflectance vs. wavelength for the visible light spectrum.

But I'm not clear how to calculate reflectance in the optical sense (https://en.wikipedia.org/wiki/Reflectance) from the outputs I have access to from the Far Field Solution Setup.

Does anyone know if I can extract reflectance from the RCS? Or is there a more obvious method I'm missing?