So, I've been processing BW (Neopan 400) for a couple of months now. Today, I did two rolls and upon drying, I noticed a yellow tinge running down the center of the roll. The edges, appear to be the normal color but this is the first time this has happened to me. I'm still new to this and would appreciate some thoughts on what may have caused this. The exposure seems normal and scans seems okay but I must have done something wrong during the process and this does not seem normal. I'm using Tmax developer and nearing the end of the container. Could developer be old? I've had it about 3 mos.