Setting Up Serial Binding with REGEX help!

Hi - Any help appreciated

This is the way the item is set up in the items file:
Switch saloon_light “Saloon Light” (Saloon) { serial="/dev/ttyAMA0@9600,REGEX(mainlight,([^:]+))" }

I get this error:
2017-03-22 08:38:04.532 [ERROR] [el.item.internal.GenericItemProvider] - Binding configuration of type ‘serial’ of item ‘saloon_light’ could not be parsed correctly.

And this is the string I’m sending from an arduino: