Are you looking for a fast flicker, or a slow pulse where you fade from one color to the other? I'm assuming you want the fast flicker.
Here is a picture of my blue settings.
For your FoC, make sure you set yours to silver (mine is yellow). Have you clicked the boxes that enable the FoC in both your emerald driver and your obsidian driver?
As for the timing, yes, the top number is the only one you can change, but if you look at the top bar (the blue one), you'll see 3 vertical lines. I slid one to the far left. I slid the other 2 to be right next to each other. If you slide those 2 and keep them right next to each other, you can adjust the timing for the bottom time values. Slide the lines to be right next to each other to create the flicker, and then place the where you want them. So, my time is 0.06 seconds, and the line is about 2/3 of the way to the right. As you can see, that would give me a time of 0.04 s on one color and 0.02 for the alternate color. Another example would be if you put the lines in the middle with a total time value of 0.08 s, then the lower boxes would change to 0.04 and 0.04.
Here is the youtube video that shows how to change the colors and play with the timing a bit.