Terri I dont remember for sure, but I do know what filters I had with me. For sure the #12 (yellow) ones are those that the natural greens look pink to red in tones. The other filters were a #25 (red) and Nikon 056 (orange). All the images that have a heavy green/yellow tones were natural browns. I have a strong felling those maybe the red filter. And yes these where all process with c-41. I metered thru filter at ISO 100. And the weather was kind overcast.
I tried to search for sample with different filter, but all ones I found where e-6. So I'm add an example of the natural colors.
I have been looking at these photos for a minute or two, and all I have to say is thanks for such a different perspective of a Joshua Tree! Especially seeing as I am sure we have all seen hundreds of photos of them, but these are just... interesting