According to a discussion on the Apple Community Support website, it seems that there are quite a few users who clearly hate OS X 10.10 Yosemite and want to go back to Mavericks, Apple's 2013 version of the MAC OS.
The reasons range from disliked colors and icons for specific configurations to broader issues reported with Wi-Fi. Most users complaining about these issues want to downgrade their operating system.
By now, most of the messages in this discussion are quite old, but that doesn't mean that all of these people are happy with their Macs anymore. Some of the latest comments show that there are still many users who want to go back to Mavericks (OS X 10.9).
Most of them are even asking for instructions on the safest way to downgrade. Unfortunately, the question doesn't seem to have been answered. The simplest and safest way to go back to Mavericks is to go back to an older backup, preferably the last one you had when you were still running OS X 10.9. And of course, if you're the type of user who uses Time Machine and makes regular backups. If not, then this solution probably isn't for you.
Another simple and effective way to downgrade your operating system is to install Mavericks from physical media. You'll need a bootable OS X 10.9 disc for this solution, and you'll need to restart your Mac while holding down the Option (Alt) key to access the OS X Installer and disk utilities. For better or worse, make sure you've backed up your important data first. The operating system can always be reinstalled. Old memories, however, will be lost forever if you partition or erase your hard drive. So before you do anything, it's best to save everything to an external drive or a partition that you don't plan on using to install the new operating system. If your Mac is from 2011 or later, you can try restoring it using the built-in Internet Recovery tool.
If you're looking to downgrade to Mavericks just because you don't like the colors, that's fine. After all, that's just a matter of taste. The same goes for those of you who have noticed a significant drop in performance after upgrading. However, if you're only looking to downgrade because your Wi-Fi isn't working properly, we suggest you hold off a bit longer, as Apple is working on a fix for the problem.
