There are so many ways this would finish beautifully and as already mentioned it's up to your taste. But since you've asked :)

Of your three displayed options - I like the green the most because of contrast, the same fabric next which offers a really muted blend (would look beautiful!) and my least favorite is white/light.

I like ideas already mentioned - a more sage green and some type of blender black or low volume black (not a hard solid) which I think would really make these patterns pop and be a very dramatic option.

Any/all of the above would be beautiful - anxious to see what you like the best!

I love the design! I am sure most what the pattern is called but not me! Could somebody please help me on this?

Do you use any patterned fabric or do you need to use fabric with a certain print to get that (pinwheel? effect?

I think the green is stunning, I would love to try pattern at some point! Thanks

Love the fabrics you are using for your quilt. I like the green best of the 3 you showed. Can't wait to see what you decide on & see the finished quilt.

I also like the green the best. Just remember - your quilt your way. If you aren't happy with your choice then you won't like the finished quilt.

Oh yessss ... for the Green ...... with envy, as I am loving it.

I love how the green is making the blocks pop.
Whereas using the same fabric just loses all your beautiful work of the octos.
Likewise the cream is just ... blah! :)

Have you considered? ... further squaring the blocks up with the green as a sashing
along with the corner tris you have already added?
Then use the terra cotta or burgundy in the fabric as cornerstones.
Would let each of those beautiful octagons float and show their stuff ...
plus create a secondary pattern.

I used a few different colors for the corners. It looked like pieced diamonds when done and I liked it.

The pattern is called "One Block Wonder" or "Kaleidoscope". A fabric with a large scale print and a contrasting background is generally used.

Lots of tutorials available online, here's a good one: https://www.youtube.com/watch?v=AYx_G83pFEw

I really like your green. The same fabric dilutes your work and to me the white is rather boring whereas the green looks dramatic.

Have you tried a terra cotta in the corners?

I would love to see a sage green, but if not then I like the dark green, and it's always nice to use something already in stash. I would also consider sashing the quilt, so that the individual blocks stand out more. It's going to be beautiful.