When I choose threads for this kind of work, I almost always go with the darker of my options. The darker color is much more likely to blend in as a shadowy tint, rather than standing out like little sparks of highlights.
Then, I whip stitched the raw, broken edges of the holes to the tulle. I angled the needle in and under as I went, creating a bit of a rolled edge and tucking in all the open ends.
Then I carefully, oh-so carefully, trimmed the excess tulle away from the back, leaving about 1/4" outside the stitching. Cutting right at the stitching would open up the holes in the netting, and the patch would come right off.
Here is the finished look.
I did some research into sewing machine history while trying to help Julia date this blouse. You can read the results of my research here.