Last night was my first experience with this developer. I mixed from the liquid concentrate purchased from Photographers Formulary. I believe it is fairly fresh as I only ordered it a month ago. The dilution used was 1:1:100 and the tap water temperature at time of mixing was 67 degrees. My clear glass beaker showed that the solution had no color which I though was a bit unusual. From what I've read here, it should have had a slight pinkish color? At any rate, I developed a 35mm roll of FP4+ for 10 minutes and moderate agitation in stainless steel reel/tank. The developer temperature at the time of development was 68 degrees. I'm aware that Mr. King recommends 70 degrees so I gave extra time above the 8.5 minutes normally used as a starting point for FP4. My film was under-developed. The images are all there but thin. The film notation on the side of the frame sprocket holes is very dim. I expected to see some sort of stain on the film and not the 'general stain' which I should see between frames but the 'image stain' which effects a frame based upon the density of the silver. After comparing negatives processed in XTOL to Pyrocat HD, I saw a very very subtle color difference with the HD negatives leaning toward the brown. Questions: 1. is the strength of the stain dependent upon the dilution or the degree of development? 2. Should I be concerned if my working solution has no color?