Creating custom color pallete

I'd just like to know what the parameters are so that I can create a custom color palette that works.
I wish I knew what was wrong with mine.
Some kind of general guide on how to make accessible color schemes would be good, because I'm not see the pattern from these examples.

Hello,

Thank you for reaching out to Jotform Support. Can you explain a bit more about your feedback so I can get a better idea of what's happening? Do you want to create your own custom color palette? Or perhaps bring in existing ones to your form? We look forward to hearing from you.