Preserving Odonata

Just wanted to see if anyone has tips for preserving the colors of Dragon and Damselflies. It seems the customary method is to put them directly into an acetone bath after capture. This will preserve the natural coloring and it will not fade as time passes. I have never tried this but all by specimens have lost their color so I am trying to get prepared for this year.
Thanks,
Tim

I drop mine in acetone before pinning them or setting them up in their permanent envelopes. Seems to work well overall, but there's still going to be variability depending on the species.

Thanks