How to allow users to pick a quantity of products they want to purchase?

Is it possible to create a purchase order and give the option for the buyer to choose two different colors in one item??

Our form has shirts and some of our people like to order a shirt in more than one of the color options.

I'm afraid that's not possible. When you add an option to your product(s), you set them up in a way that only one option can be selected (e.g. if you setup 3 colors, then only 1 color will be picked for that item).

Related guide: How-to-Add-Options-to-Payment-Forms

What you can do is use the ADD QUANTITY feature on top of the ADD OPTIONS feature. And I'm seeing you're done setting this up on this form https://www.jotform.com/janethenry/Absolute_Impressions 

This would mean users can pick which color they want and how many they want.