I agree with the others on the non-green sashing and no corner-stars
Then go with the background fabric for the sashing.
You could do some really nice quilting in the ashing area, which would really let those stars shine forth!
And too, I like Dunster's on-point suggestion.
I'll take it a step further beyond sashing ... and do alternating blocks of the background fabric ..... and would even audition the alternate blocks in the pale green. Again, some pretty quilting will go nicely into those alternating blocks and still let the stars shine nice and bright!