filtering a Value List

I have field, stock color, where sales people can select from 14 different stock colors. If the price the card as metallic (field: metallic card = Yes) how can the list of colors be reduced?
thanks
Jim
thanks
Jim
Support for SeedCode
http://n7lj-g8dy.accessdomain.com/support/
http://n7lj-g8dy.accessdomain.com/support/viewtopic.php?f=12&t=1448