Multiple Option Select

I need for my customers to be able to select several colors of a single product. For Example, they order a flowers and have a choice of 3 colors. I would like to create 1 option with a multiple select input where they hold control (pc) and select 3 colors. Is this possible?

I believe the options interface would prefer you to use checkboxes in this instance. I don’t believe multi-select is an option (for options).