I don't know if it's pertinent any more since S&S is gone, but #4 looks the closest to my eye, even though the white balance is not identical between the video and your sample. The blue tinge in the video is just the sky reflecting off of everything and a polarization filter would get rid of it.
Yes, an 18% gray card in both shots would be ideal, and that's what I did when taking my own reference photos of UP ballast in Weber Canyon a long time ago with my 35mm film Nikons. I also picked up a dozen ballast stones of different colors to be able to physically match the colors with my naked eyeballs at home under my layout lights.
As for ballast size...when I compared the rock size of #4 between the ties on the outsides of the rails, it looks really close...but, when I compare the rock size laying on the center of the concrete ties, #1 looks to be more correct. I don't know what that's all about, but, if it were me I'd try to match both the rock size and the color mixture of #4 as well as I could.
That's my two-bits worth!
Cheerio!
Bob Gilmore