Manual focus works the same on your K-3 as on the K5-series cameras with one exception. On the K-3 you have focus peaking in live view. Using the AF system for focus confirm should be somewhat more dependable with the K-3 and faster lenses (f/2.8 and wider) and about the same with slower lenses.
The color artifacts you are seeing are not related to focus accuracy:
- Purple/blue fringing may be due to longitudinal chromatic aberration which is a lens characteristic and present regardless of the camera used. It may also be the hard-to-characterize "purple fringing" that is an artifact of digital capture that is triggered by some lenses.
- A greenish border is lateral chromatic aberration and is also a lens characteristic.
All that being said, you may indeed be having problems managing manual focus on your K-3. Missed focus is incredibly easy to see on the high resolution K-3 image. So is inherent softness. I do not have hands-on experience with either of your lenses, but I don't believe that either has a reputation for softness. I would expect that both would perform at least as well on your K-3 as on the K-5II.*
Steve
* For an equivalent size final image