You said..."I've read on here that chameleons change color due to emotional response, I'm guessing veiled do the same. What are some normal color patterns for veiled and what is the emotional response for them?"...they change color not only due to emotional response but will also change to lighter colors when they are too warm and darker colors when they are trying to warm up.
The colors presented with the emotions are usually accompanied by posture too. Together they form a kind of communication.
A male veiled meeting another male veiled will inflate his body vertically, brighten his colors, inflate his gular pouch, hiss, gape, coil and uncoil his tail, hold one hand close to his chin, etc. All of this is intended to show the other chameleon that he is the best and defending his territory. If the other male doesn't leave quickly then things will escalate.
http://pets.webshots.com/photo/1061862356029838229vqpECc
http://pets.webshots.com/photo/1061861758029838229dCUnka
If a male veiled sees a receptive female veiled, he will brighten his colors, inflate his body vertically, bob his head and approach her to mount her.
http://pets.webshots.com/photo/1147641220056094951bEUlFs
If a receptive female veiled meets a male she will keep her body thin and likely hold it close to the branch, likely raise her back end slightly and move slowly away from the male while maintaining her green coloration with bright blue dots and mustard colored splotches.
http://www.repticzone.com/photogallery/viewphoto.php/20820/Chameleons/Lizards/
A female can show the blue spots and mustard splotches when gravid/non-receptive when not in the presence of a male.
http://pets.webshots.com/photo/1147634656056094951eGlxIk
http://www.repticzone.com/photogallery/viewphoto.php/30546/Chameleons/Lizards/
http://www.repticzone.com/photogallery/viewphoto.php/18203/Chameleons/Lizards/
If a non-receptive/gravid female veiled meets a male veiled she will inflate her body, hiss, gape, lunge at the male if he is close enough, rock back and forth, darken her background color to almost a black. If the male doesn't leave, then she will attack.
http://www.repticzone.com/photogallery/viewphoto.php/27821/Chameleons/Lizards/
http://www.repticzone.com/photogallery/viewphoto.php/22861/Chameleons/Lizards/
http://www.repticzone.com/photogallery/viewphoto.php/21234/Chameleons/Lizards/
When the veileds are put in a new situation they will get dots and the colors will change...I usually refer to this as them showing apprehension.