I am wondering if this is the way WordPress try to force to go Premium?
Actually, it's the opposite! The update was made in preparation to update more themes with free color palettes. Only a few themes have them so far though (check out Appearance > Customize > Colors in the Writr preview), and it might a little time for more to get added. But they will!
In your case, I think the colors changing was due to a bug (that we've fixed now) but some color settings got "stuck" in your blog. That happened to a few people, and I'm working through the forums to try to find all the cases and help fix them.
I took a look at https://theorientnomad.wordpress.com/ and set the colors back to what I think are the right ones. Could you take a look now and let me know if it looks as expected?