I have been developing C-41 for more than a year, but I'm pretty new to E6. This is my 6th roll of E6, but the first time I worked with RDP. I have finished my stock of Kodak E100VS (120 & 35mm,) and started off with my fresh 100ft reel of RDP. I had pretty satisfactory results with E100VS all around, but this time I had a pretty noticeable pinkish color on the exposed edge of 35mm film base. I am on Kodak chemicals, and are well replenished. One mistake is I was concentrating too much on the soap opera and my first development was left extented to 7:30. However, exposure is pretty much fine, since some possible under exposure is assumed with my 30+ year old Nikon. Timing in other steps are pretty much followed as instructed.
What went wrong here? What causes the pink color on the film base? Or, is that considered normal for Fuji slides? According to my experience, the pinkish cast is quite noticeable for Velvia RVP100 (non-F) but not for Provia.