bearisgray

How about trying a dark brown?

Mariposa

I vote for the blue~~

Tartan

Cute blocks and I vote for the blue. If you are thinking the blue river will run into the blue background? Bonus! I would add a couple of more alligators on the blue background sashing as if they are swimming around the other blocks.
If you think it makes it too much blue , I'd use green sashing as you have a lot of that in the blocks and maybe add a couple of more monkeys in the sashing.

sewingsuz

Red for me!

ManiacQuilter2

Blue is more calming. Love you socks too!!

Dina

I like the blue. It is going to be a very cute quilt, no matter which you select.! (And I like your socks too...)

Dina

Barb in Louisiana

I like the playfulness of the red. The blue is much calmer.

feline fanatic

I would love to see each block framed in a small border maybe 1/2" wide or less and then blue sashing. The problem I have with the blue sashing is the river and lake seem to disappear into it. But I think a small frame would solve help your cute blocks to stand out more. Now for the issue of what color to chose for the "frame". The red would certainly pop and keep in with the theme of bright primary colors. But it may be too much pop. I have to audition things like that.

thelazyquilter

red. More gender neutral and the red makes those blocks pop! Really cute!

quiltingcandy

Why not use both colors? I would frame each block in red then use the blue for the sashing.