Hi there. Was dumbfounded for a while when setting up an airtable → miro card widget Zap in zapier. Setting card color is possible, but requires the hex color code to have a preceding #. That’s fine, but it’s not documented in an easily-accessible way outside of the API docs and not all apps require it. The Miro docs are a bit obtuse for non-developer pro users, and the error returned via zapier was just ‘method argument.’ Searching for that in the API docs didn’t lead me anywhere. Digging around and reading carefully, noticed the need for #, but I recommend making more verbose error codes or being clear about data validation requirements somehow. 400-Bad Request did not make it clear. 

Thanks for considering.