After Ink asked about these colors for his Fi 156, I decided this would be a good one for discussion.
I did a lot of research on RLM 79 in 2006 for Targetware. I made a chart showing all the RGB numbers I could find online. Here it is-

It's pretty obvious there was no consensus on this color within the online skinning community at the time!!!

For Ink, I got out the old Monogram Guide chips and the new Classic Publication chips. I didn't bother with Ullmann's chips which I think are too glossy and deep to use, or the Egale Additions chips. I didn't think it would make a difference unless I had a color spectrum analyzer.
Using my eyeball, which isn't too accurate or scientific, I came up with this-

I didn't have a nice chart made for 78 and I don't feel like making one now, but I can tell you the online RGB RLM charts I collected show as diverse a color range for 78 from green is to straight gray. Here is my eyeball match-
OK, that's just a starting point I hope. maybe both of those colors are too light? Or a little off?
I'm sure some of you have your own matches for 78/79 and maybe even a few accurately matched RGB numbers to add? Baron, Jester, I know both of you have your own matches ready

Let's have them please, along with what chips, if any, you are using to derive your color