Not too asthetically pleasing but that's probably not why one would get an air filter, and has a very strong output.

I used mainly the automatic setting. The owners manual says that the three colors are red, yellow, and blue. Mine are dark pink, light pink, and blue. That's a bit of a discrepancy. I also notice that it spends most of the time in the middle setting (moderate particles detected#. It takes a lot of time to actually stay in the blue setting #minimum particles detected). It fluctuates a lot between settings and sometimes it's hard to tell if it's sensor capabilities are always accurate, but I have no reason to believe that they're not working, it's just a new feature. It's hard to imagine that indoor air quality could be that bad.
It's simple to use and easy to understand. I have 3 Alen filters now and have never had any problems with them.