I have set up my bot in landing page mode with a custom background. When I embedded the bot in my site the background was also displayed there, what was a good thing.
But now suddenly the background is disappeared, and it has a plain white background now.
I have seen your conversation with customer care team. Chatbots in embed mode have a transparent background by nature. So whatever color is in the background of the embed chatbot, that will be the one you are seeing.
Only chatbots in landing page mode has a custom background option.
That being said, there was a minor update in the product, where we had to change the background of embed bot from transparent to white.
We have reverted our changes. Embed bot is back to having a transparent background. So now everything should be good.