I am designing a rod with Blue Heron colors in mind where the blanks will be in a naturally grey clear gloss finish. I am looking for a good navy blue thread color. What I have found so far doesn't quite get to the deep inky indigo blue I would prefer. Does anyone have any suggestions? Once I lay out the handle, I will be sure to try out a few colors in between the real seat arbors before wrapping the guides. Thanks!

Have you looked at Fuji Ultra Poly? [anglersresource.net]

Another option is to visit an embroidery store and pick from the hundreds of Madeira Polyneon thread colors. They will require CP.

It might be helpful if you could list the threads you've tried and if you used CP or if they were NOCP threads.
Thanks.

Get some pearlized dust and create the color you want. Mix the dust with thread epoxy and test it on top of the thread you choose. I'd wrap about 4" of thread on a scrap blank section and test your color creations. Blue herons have several more colors you can try to match for accents. Sounds like a really cool project. VooDoo.

Have you looked at ProWrap Blurple 464?

I have to second Mark’s suggestion. I’m mostly building now with UltraPoly, without CP treated threads or coating, with tone on tone Voodoo Dust. I especially like their metallic pigments for this method. I haven’t used this exact combination, but the ultra poly dark blue with Voodoo Dust Voodoo blue jives with what I’ve liked in maroon, Dunn, and turquoise spectrums. I usually mix one to two of their provided little scoops with 10ml total of rod finish. You can still see the thread work but the color is enriched. I don’t know how a second thread color would show. I’ve tried posting pictures a bunch of times and they never upload even though I can log in to the photo section. I’ve followed the instructions to a tee. I’m done trying.

Pearlized dust? I'm checking this stuff out!

I'm not a fan of Pac Bay but I have had luck with their blue nylon thread. Look into it and see if it meets your needs.

Thanks everyone for the guidance and recommendations. I am looking forward to experimenting more.