I vote for Navy or Hunter,in a tonal or solid, for sashing. That way you are not adding another color and the darker value will tone down the look of the overall quilt and your blocks will pop. I don't think they are ugly at all!
Take a few blocks with you to the fabric store and lay them out on some different fabrics that you like and you will see what the sashing would look like. Have fun, I think you did great so far.