* Initialize compare hex once in controller, fallback if color missing
This PR adds a fallback color choice when there are missing
bg_color_hex or text_color_hex (this is likely going to become more
common as we only show the bg_color_hex in the form).
The choices (black and white) may not be correct - this "custom, or
default" value choice should likely be made in a decorator or on the
model instead.
Addresses an error reported in
https://app.honeybadger.io/projects/66984/faults/83671065
* typo: Attribute name is text_color_hex
2fbfd68172