Wix store - selecting multiple options at once

Hi.

Let's say I want to buy 4of the same item but I want to buy all the colors available:

Red, Blue, Green, Yellow

Then I want the user to have an option to click on and have an automatic discount without a coupon (can do this by creating another option that changes the price to a discounted one in the product option value manager)

As it stands, this is not possible to do in the same product page due to not being able to select multiple options (colors) and calculate the price accordingly.

*** As a work around, I thought about creating check boxes in a custom product page and adding the code that populates the checked boxes' info into a text input field that is connected to customTextField field in the store database. So I could collect the selected color values in a manual fashion and let the buyer only select the quantity for the price calculation. Unfortunately the field is Read Only :(

If you understand the logic here and where I am falling short and if you have a code or a work around I'd greatly appreciate it.

Thank you.