According to Mental Floss, The Solo Cup company started making them as early as the 30s, but the big marketing push came in the 70s.
Red cups for house parties and white foam cups for social settings
Nothing screams house party more than a red cup. House parties you can be yourself, be as corny as you like and the games you play make the plastic cup a great accessory. Styrofoam cups, on the other hand, make great accessories at events that would typically have great lighting, Instagrammable settings and product placement.
Red cups place attention on the cup, White cups is a blank canvas
This one's easy - look at any pose and the red cup will be noticed from far. But if you’ve got a white cup, you’ve basically got a blank canvas to work with.
Red cups are more noticeable from further away, White cups look great for close-ups
Red cups are definitely more noticeable from far away. You can look from far and see someone is holding a red part cup. But when you want to do a detailed close-up, white cups work great on many backgrounds.
ConclusionAll in all, it depends on your event and what you are trying to achieve.
If you’re having a house party then yeah, the red cup is easy to buy in the right off licence. But if you have a wedding, launch party or branding event, then a white foam cup gives you the blank canvas to do your thing.