Eddie takes stunning NarrowBand images with, I think, a Mono camera. From the sound of it, you guys might be using a colour camera which may add unwanted complexity??. A Mono camera gives all the images in grayscale and you assign whatever colour you like: HOS = Ha-Red, OIII-Green, SII-Blue. SHO ("Hubble Colours") = SII-Red, Ha-Green, OIII-Blue. There are other combinations as well.
A good intro -
http://starizona.com/acb/ccd/advimnarrow.aspx
Charles