I'm about to start the processing of some slides with the Fuji 6-bath kit.
The concentrates have been opened for some months, and I see that the first developer I've mixed has a light brown colour. Is it OK?
Is there any way to test it before proceeding?
Most likely it is still ok. The only meaningful test is an E6 test clip. Anything but an E6 test clip (e.g. with a B&W film clip, E6 FD is a strong B&W developer) would need a reference clip developed with fresh FD, and would therefore have to be prepared when the kit is fresh.
I think the colour must not go past that you would expect to see in straw. I have kept some over 8 months in a part used bottle and it was still useable.
Well, I think you both are right. The results are excellent!
And I opened these chemicals last July! It's around 9 months now in the original part used bottles...