Dropdown - Proof vs Production

Scenario: 

Variable product has an image that the user selects and the way they are produced we need the print file to come out with a different looking image where the white is replaced with magenta. But we need the preview that the customer see's to show white as white. The problem with a regular dropdown is the print file is coming out as the preview! We really need the print file to have magenta where the white would be on the image. Solution:Create a txt file as you normally would for a dropdown. The Block function to use would still be dropdown.The text file should look something like this: 

Option 1::::{{~/Storage/1/1/0/Assets/Images/Online/Image_1.pdf^^^^

~/Storage/1/1/0/Assets/Images/Production/Image_1.pdf}};

Option 2::::{{~/Storage/1/1/0/Assets/Images/Online/Image_2.pdf^^^^

~/Storage/1/1/0/Assets/Images/Production/Image_2.pdf}};

Notice that there are two paths and images being referenced. The first is for proofing the second is for production.