Bought some and they are now fitted on the Turkish Delight. Only one ride in and they feel the same as the regular marathons, grippy and solid.
They are more yellow than Gum, although i think the turkish green makes it look particularly yellower. So much so that my brown Brooks B17 with copper rivets looks odd. So I'm now waiting for the Brooks C17s in black with gum to arrive, which I think will balance everything out again.