Hey guys, I am trying to build the simplest circuit that can achieve oscillating two LEDs at different frequencies. I also want the LEDs to not oscillate down to 0, as in the LEDs just vary in brightness but never turn off.

Here is a graph, Brightness vs. Time, representing my goal for the two LEDs. I have tried to make my own circuit but it doesn't yield the results I want (Not the specific values, just the shape of the graph).

I'm assuming that I may have to make two separate circuits but I'm not sure. Let me know what y'all think.