You certainly need to patch the Edge's firmware, but it's weird because I have a friend who has a 66sr so one of the last GPS released and it works without patching the firmware with the V6, it should be the same, but maybe that it is necessary to modify an internal file:
"it is effectively the renaming (or deletion) of the file" Mountain.kmtf "which improves the colors on some Edge."
I do not know what to say because I do not know the Edge except mine Edge 705 .....