Since I'm running low on colours I want to use for this series of towels, I wound up with a value difference that was greater than my eye liked. I knew the weft for the towel body would make the difference less, but I wasn't happy with either of the solids in the warp for the hem weft. So I used something else entirely.
The two larger tubes are the colours in the warp. The smaller tube is what I used for the hem. The colour is about the same value of the brown/tan, but more greyed. It brings the value of the pale grey down so that there is less value contrast and helps the hem to blend in better with the body of the towel, I feel. The towel body is a bit 'brighter' so the hem is less obvious to my eye.
That's my story...sticking to it...(Colours not completely accurate in photo)