Is the YRGB Kit for this light available for preorder anywhere? I could not find it anywhere.
Also is it safe to assume the kit is separate from the light and can be bought by itself when it becomes available?
Not from where I ordered my light, but maybe elsewhere. I have a feeling that the kits will be a bit later than the initial release of the standard light.
As to if it can be bought separately and retrofitted: If Eagletac have been sensible, then yes. But perhaps not...
From Eagletac:
"Extra signal connection through the body tube(pre-installed)
Extra tailcap w/switch and tail-standing ability"
Hopefully this extra signal connection is already present in the standard model and just needs the extra tailcap to connect to it, rather than having a different body for the kit version. That is the sensible way to do things from my viewpoint.
It might be worth checking with Eagletac though, to make sure it is the case.