I've just finished a series of prints on Forte Polywarmtone FB in Ilford Warmtone developer. After reviewing them, I've noticed that 3 of the prints have very strong yellowing on the image and borders. As I tend to experiment a lot, I gave some of the prints 1.5 - 2 mins underdevelopment during the session to achieve a warmer look. The other prints were given 4 minutes. All prints were soaked overnight, washed in running water, hypo cleared and washed again for 10- 15 mins in running water. Is this yellowing normal with over exposing and under developing? Or has there been a problem with the fix or washing? Thanks.