[Plugin: Custom Contact Forms] Multiple options

I must be missing something. I’d like the form user to be able to select multiple options, for example, to be able to select two out of three colours listed. For the life of me I can’t get it to work.

I know I could have multiple checkboxes but then how do I put a title above the checkboxes, for example, ‘What colours do you want?”

https://www.ads-software.com/extend/plugins/custom-contact-forms/