I have CZs that came with red, 1mm, fiber rods for the front sight. My Gunsmith replaces the red with green and flattens the fiber closer to a 1.5mm diameter. As I age, the red is harder to pick up but green stands out more and is easier to pick up. A little fatter dot (1.5mm rather than the stock 1mm) also aids in picking up the front sight dot.
Changing the color and size makes it easier (and quicker). I don't think that it adds to accuracy; it's just easier and, therefore, more fun for me to shoot.
Otherwise, I have the sights changed to TruGlo TFX Pro Sights. I picked up a P-01 with these sights already installed and found them the best aftermarket sights that I have tried. They are green fiber (2 rear; 1 front) with self-illuminating behind the fiber. A red/orange ring around the front fiber. These get to be expensive with several CZs but enjoying shooting is a big part of shooting at my age. I expect to run-out my time with these pistols and sights so the expense isn't a problem.
HTH