Grant is correct. As one who has operated in and out of Pavehawks for the past 14 years, I can tell you that they are now coming back overall gunship gray; we call it AFSOC gray since AFSOC is taking over as the lead agency for CSAR in the USAF (was ACC and thank god that's changed). Hell, my own squadron has 6 HH-60G's and some are Euro and some are gray. There's also a mix of Block 152/162 upgrades out there in each squadron, the latest mod were seeing is the removal of the HF "towel rack" antenna on the lower left tail boom (since we have SATCOM), plume detectors on the upper nose, chaff and flare boxes moved slightly forward on the tail boom, and externally mounted guns and ammo bins to free up much needed cabin space. The latter has always been a problem for us since the -60 was never really meant to be a CSAR bird. With the internal aux tanks, ammo bins and gear, there's hardly any room left for us and out gear. BTW, ESSS was never meant as a combat configuration. It was designed for ferry flights only and combat/operational use came about out of necessity. We in the USAF don't use ESSS due to it's limitations on airspeed, gun azimuths, gunner situational awareness, and team ingress/egress out of the back end of the helicopter.
The only birds I saw during OIF painted in a desert scheme were USAF Reserve birds from the 301st RQS out of Patrick, and the 305th RQS out of Davis Monthan. All other Pavehawks were either gunship gray or Euro. While deployed to OEF I saw no Pavehawks in a desert scheme. They were either gray or Euro.
As far as the Tan/Sand and gray....have never seen any either operationally or during an exercise. The most current desert scheme from OIF was similar to the 3-tone desert BDU's. Almost the exact same colors.