I frequently get asked why the standard Evaporation gimmick is Orange SunnyD. There are several reasons why this is the main gimmicked bottle. One of these reasons is visibility.
For example if you used milk in the classic Magic Milk Pitcher the white liquid would virtually disappear if you were performing against a white background. You will find white backgrounds in places like:
School Gyms: Very frequently when doing school assemblies you will have a white or light gray gym wall behind you.
Theaters: I’ve performed at many performance venues in variety shows where my show took place in front of a giant white movies screen that another act was using.
Outdoor Shows: When performing at a fair or festival usually your stage will have a canopy with a walled side behind you. The majority of these that I have encountered are white.
By using a juice that is bright colored and not a color that typically appears as the main color of a backdrop you are increasing visibility for the trick. I’m sure at some point I’ve done a show in front of a bright orange background, but those are few and far between. Of course to solve this problem 100% of the time you could simply order two Evaporation gimmicks, one in orange and one in red.