Hmmm... could be dominant and subordinate male behaviour, but really sounds like male and female behaviour. Alot like bearded dragons. The males head bob and the females arm wave. Color is a funny thing with uros, especially Malis due to females who mimic males at times in coloration. Apparently these females are more aggressive as well if I remember correctly. There are several websites on kingsnake.com to compare male and female coloration. Deer Fern Farms is a good one.

Good luck!! I am pretty sure I have a female based on age and coloration. I am thinking about getting a male and would really like to try and breed these amazing lizards!!