Cathy, I experienced the same thing last year—red exposed seeds. The forum was so helpful in explaining to me that those are exogenous seeds (outside of the hip). In my case, the hips that have them, are generally also “bursting at the seams” with other seeds. The redness may be from the sun scalding those exposed seeds. I received so much good information from people ont his forum regarding this phenomenon. You can probably find the thread by going to advanced search in the upper right hand corner and typing in the word exogenous. This is such a wonderful educational tool.
Also, in my case, it was mainly the open pollinated hips that did this. I sowed the exogenous seeds with the other open pollinated seed, realizing I had nothing to lose. Looking back, I wish I’d sown them separately just to see how the results compared.