If you already have a folder at
~/Library/Application Support/Coda/Modesmove it (or remove it if it's empty).
Check out this repository:
cd ~/Library/Application\ Support/Coda git clone --recursive git://github.com/bobthecow/coda-modes.git Modes
If you have additional syntax modes in your old
Modesfolder, copy them into this folder.
SubEthaEdit in the paths above.