Now that I'm thinking straight, I am curious about what exactly you're looking for. Are you looking to buy some (blue?) paint that matches the color 539?
539 "IS" your color code... are you looking for a paint formula?
I did a quick search for "539" in this forum and right away I got this hit. There are likely more too.
http://67-72chevytrucks.com/vboard/s...&highlight=539
Please provide more details and we will try to help.