How the heck does nature create a multi-colored pumice? I only came across one piece like this one, there was a lot of reddish-brown pumice found in that area. I contacted a geologist at the natural museum who said that couldn't explain how the colors were created, what he really found strange was the fact that there were no volcanos anywhere near where these stones were being found.

Thank you very much for the links. I didn't think this was pumice when I found it but it floats in water and if you look at it under a microscope it looks like glass. If I can find the close-up photos, I'll share them later.

This is a pretty specimen. My favorite of all your specimens yet!

I was wondering, but doubting, if it would float. With all the "glassy" silica I can see in your pictures I figured it would be too heavy.
Great specimen. It would be interesting to nail down the source.

In the link about the Lapilli Tuff from the Pinnacles Volcanic Formation they are leaning toward Glauconite for the cause of the green color. Far be it for me to say but I have to wonder if it's not Prehnite in this specimen? A fluorescence test with UV light may shed some light?

Of course there are several cool looking little crystals or blebs visible in your close-ups, but it's the little red blebs, or crystals, that I think are really interesting. Beautiful little things! They could be a lot of things including Hematite or Iron Oxide, but I wonder if they are "Analcime"? Your first picture has the red color dispersed throughout the matrix but these are definitely singular.
From the Wiki-link on Analcime included below;
"When on matrix the mineral takes on a granular habit, crystals become anhedral."
And it says Analcime has been found at Searles Lake, CA, although that might be the clear variety?
Anyway, thank you for all the fine pictures of this very interesting specimen! Have a good time trying to identify all of it's components  and discovery of it's source.
Keep us posted, we'd like to know what you discover!

https://en.wikipedia.org/wiki/Analcime

And the more you learn, the more questions you have.