Foveon 'Look', 'Sigma Color'
Auto white balance issue? I am not a Sigma user, I know Sigma's have an odd colour palette, and I know they change palette across ISO... but I see no reason you should get that level of color shifting over two exposures moments apart aside from a white balance issue... or malfunction.
|Common Flashwing by digimania|
from canon dslr
|The Marilyn impersonator by Lee8282|
from Blowing in the Wind (Nature)