Something that I've wanted Varmilo to do for quite some time: Offer keysets with transparent characters. Any of the above keysets would be better for me if the LEDs were visible through the letters.
I also notice that Varmilo has a predilection for light pastel colors. It's a kind of signature for Varmilo, isn't it?
The blue and pink keyset looks good aesthetically -- those keys and the gray case would match a suit, tie and dress shirt combination perfectly -- but I can't really see myself typing on a pink keyboard. Perhaps if the blue and pink were reversed and blue were dominant, I'd think about it. What about light purple keys for black cases, light orange and gray keys for gray or black cases, and two different shades of blue for white, gray and black cases? Also, I'm not really a fan of mint green. Chartreuse and black might be nice with a black case, though chartreuse doesn't really match your aesthetic.
One last thing:
A fair number of people have bought more than one VB87M. Here's why I haven't: the battery isn't removable and the USB connection is only for charging. It annoys me that once the battery dies, I won't be able to use the keyboard. If the USB connection could be used for typing as well as charging, I'd be more comfortable buying an input device with a bluetooth feature that could become useless in a matter of years. I might try tracking down and installing a replacement battery after it happens, but that's clearly going to be a hassle.