I had a similar experience this summer while cleansing heavily for parasites. I know my liver was congested, putting alot of stress on my kidneys as well. I had the oddest feeling that something wasn't right. I was getting some color, but the amount of time in the sun would have normally produced more of a tan.
This lasted a couple of months, then as my liver issues seemed to get better, I started to develop a tan, but it never was normal for my skin. I have not done a Liver Flush yet, just let time work it out and my liver catch up with the toxins.
This thought crossed my mind several times that something was going on internally blocking my body from producing color. I did not really attribute it to my liver though, just with all the stuff going on. Maybe there is a connection with the liver?