Panaracer Pasela PT are an excellent road/light touring tan sidewall tire, but they're lighter than the Marathon, which is more of a heavy duty loaded touring/urban tire. There's also the Rivendell Ruffy Tuffy, which are decent but I like the Pasela PT more.
The Black/Tan version of the Michelin World Tour is in the same genre as the Marathon but not as nice, and I think it's only been made in 27 and 590. I'm not sure it's made at all anymore.
There are a couple sizes of the Halo Twin Rail in black/tan. I don't really have an opinion about these but the puncture protected ones are kind of in the hybrid/touring genre like the Marathon.