Colors from Symbology change when exporting to PDF

Question

I have a point layer that I am symbolized by graduated symbols. I am also varying colors by another index field. when I view the map in the layout view, everything looks great. When I export the map to pdf, the varied colors change somewhat randomly. The work around is to use .png or .tiff, but I prefer .pdf and it is perplexing why this happens in the first place.
This is the Layout View

This is the .pdf.

Teri_Dane · Answer

I found that when you export to PDF, you need to check the "Output as image" under Compression to keep all colors.

JeffreyKeck · Answer

I had a simalr problem exporting to any file format. One shapefile in the map would show up as a different color in the exported image. Solved by making a copy of the problematic shapefile (right click on shapefile=>data=> export features) and loading the copy. Turned off the original. Turned on the copy. The copy showed up fine in the exported image.

Robert_LeClair · Answer

Thank you for the feedback Timothy.  Interesting that it was reproducible on a totally different dataset.  Agree that I'm not sure if my response is/was a solution or not but as long as it's working now, I guess that's a win!