Another bug (mentioned in my reply above) is that the 'Color code' and 'Clear' fields are hidden.
See the generated code:
As you can see, the 'Color code' input (rwmb-color) has data-options 'hide' option set to true which I guess adds the "display: none;" line in its "style" attribute. And the button input has the 'hidden' class which, by WordPress core ui CSS also produces display: none;
If another plugin is using Iris, it would be best that your code anticipates possible conflicts and makes sure that your Iris elements, that are meant to be visible, stay visible.
P.S. I solved my issue with some !important CSS that forces those fields to display: inline-block; but it would be best if your code does it by default. Here's the code if anyone else needs it: