Besides the weights and barbecue, I have a two-toned neck, too. I am somewhat dark skinned with Japanese ancestry. In the sun my skin gets very dark but now I am either avoiding the sun or using sunscreen. The radiated area looks like a band of suntan and under my chin is white, white, white. I'll try anything...even the BareMinerals, if it works! (I'll put it on while I am smoking the ribs!)
Ed