Diving Beneath the Sea of Stellar Activity: Chromatic Radial Velocities of the Young AU Mic Planetary System

We present updated radial-velocity (RV) analyses of the AU Mic system. is a young (22 Myr) early M dwarf known to host two transiting planets - $P_{b}\sim8.46$ days, $R_{b}=4.38_{-0.18}^{+0.18}\ R_{\oplus}$, $P_{c}\sim18.86$ $R_{c}=3.51_{-0.16}^{+0.16}\ R_{\oplus}$. With visible RVs from CARMENES-VIS, CHIRON, HARPS, HIRES, {\sc {\textsc{Minerva}}}-Australis, and TRES, as well near-infrared (NIR) CARMENES-NIR, CSHELL, IRD, iSHELL, NIRSPEC, SPIRou, we provide $5\sigma$ upper limit mass c $M_{c}\leq20.13\ M_{\oplus}$ refined b $M_{b}=20.12_{-1.57}^{+1.72}\ M_{\oplus}$. Used in our new RV modeling toolkit exploit wavelength dependence stellar activity via wavelength-dependent Gaussian processes. By obtaining near-simultaneous RVs, also compute temporal evolution RV-``color'' introduce regressional method aid isolating Keplerian signals when future works. Using multi-wavelength process model, demonstrate ability recover injected at significance with semi-amplitudes down $\approx$ 10\,m\,s$^{-1}$ ephemeris, more than an order magnitude below amplitude. However, find that accuracy recovered $\sim$50\% for such model.