Image pulsing white yellow orange

[scmc0011 0]

Hi i upgraded a sysytem to some sharp ccds 540 tvl vari focal domes. The cameras are powered from an 12 v dc 5 a power supply. the problem is that the image has a pulsing colour change from white to yellow then orange back to white on all cameras, Can anyone help or has any one had this before. I have attached a link to a recording

 

http://www.megaupload.com/?d=PIOL52DP

 

Thanks