Longer answer: The vision sensor is very finicky. I have found it very unreliable. Preferably, you would use an Optical Sensor if you were sensing color in a fairly close range. The Vision Sensor can accomplish these purposes though, and there are a lot of threads about it like this one. Use the search bar and you should be able to find some examples.
LOL, unfortunately the inertial sensor will not do perfect turns for you. Here are some previous threads that may be helpful or interesting. The overall synopsis is: use a PID loop with the Inertial Sensor values.
If you want to learn about PID, I will quote myself and say this should help. A lot.