YOu can get custom mixed colors from alot of auto supply stores..... I had 2 cans of purple peral mixed up at the local NAPA store.... the price is not bad at all.... basically you have to buy a pint of automotive paint.... they will thin it out for you and mix it into the cans... cost for my color was 30 us dollars that was for the pint and 2 spray cans.... 1 can should be enough for any atx mid case.....
good luck