Dropdownlist styles are lost on a post back

I have a dropdownlist that I try to set the test color of the items in the list.  This dropdownlist is in an update panel.  When an update occurs the styles on the items are lost.  I have tried setting the styles in both a custom derived dropdownlist and in the pageload on a normal dropdown list.  Does anyone know how to correct this?
 
Thanks
 
Dave
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