You have your L,R,G and B image in fits format , now it is time to create a color image. This tutorial shows you how, You can download the software (trial version) and images in the links below.
If you have questions or requests for tutoring, send an email to christian at itelescope.net
You can download sample files here https://go.itelescope.net/Video/SkyTo...
Software download is here http://www.ccdstack.com/CCDStack2/CCD...
This plugin should be used for best alignment results
http://www.ccdware.com/Files/CCDISP21...