For a nice rich black in flexi using no color correction on the redering intent tab under the vector & text on the cmyk & others category, I use 15 15 15 100 and it prints a perfect rich black.
Reds can be achieved in a couple different ways. Your environment is a very important part of printing consistant.
But as luggnut stated, you need to learn the color side of it. I have been creating profiles for 3 years and I still have alot to learn. So just start reading and applying your knowledge.