Be careful when creating your own feed item. On my first attempt at creating my own feed item I sent up an SVG file (I assume this is the issue) as the image URL and now my app crashes at launch.
Currently waiting for a specialist to take a look to get access back 
Turns out it wasn’t the SVG image, all attempts to create a feed item have crashed my app so far now.
Just sent this feed in and my Android app crashes:
{
“account_id”: “”,
“type”:“basic”,
“url”: “https://www.google.co.uk”,
“params[title]”: “My custom item”,
“params[image_url]”: “https://i.imgur.com/sLM61uf.jpg”,
“params[background_color]”: “#FCF1EE”,
“params[body_color]”: “#FCF1EE”,
“params[title_color]”: “#333”,
“params[body]”: “Some body text to display”
}
[edit] both through my own client as form data and through the playground as the above json
02-09 13:14:37.345 10149 22372 22372 E AndroidRuntime: FATAL EXCEPTION: main
02-09 13:14:37.345 10149 22372 22372 E AndroidRuntime: Process: co.uk.getmondo, PID: 22372
02-09 13:14:37.345 10149 22372 22372 E AndroidRuntime: java.lang.IllegalArgumentException: Unknown color
Seems like it doesn’t like one of the colours, possibly the abbreviated #333
