So what the heck. Let's shellac the blue tape and see what happens. Start with some Zinnser Bulls Eye Amber shellac, using a disposable foam brush for minimal cleanup. You can see the small sample of bar tape I used as a test. It looked fine, but I really wouldn't know the results until I saw it on the bike.
I started to apply the shellac to the twine and tape on one side...see the difference? I think it looks much better.
After applying shellac to both sides, the bars look like this:
After the shellac dried, the bars took on kind of a greenish antique patina. I'm thinking they would really match the dark green B-17 saddle well...not that I'm going to run out and buy one but that's just an observation. It would certainly be much cheaper to find and buy some natural cork if I wanted to match my saddle perfectly, but this looks just fine to me and is a unique look amongst all my other bikes. So I'll go with it for a while.
More pics on the way...