Alternating LEDs for various PWM waveforms

[Hypernurbs]

Hi all

I have a PWM modulated signal, coming from Druid's TapLFO, swinging between 0V to 5V. What I want is 2 LEDs alternating and with the shortest 'off state' as possible, so I can use them with two LDRs. And I also want to have the level of brightness adjustable for each LED, starting off with full brightness/no visible waveform. Yes, I want a lot, I know. 

So I created this schematic on my breadboard. It works nicely except it takes a small bit of turning the pots to get to the point where theres no 'off state' from the LEDs at all.

Does this schematic seem logical for you? I know if it works it works but maybe someone has tips to improve it?

The pots are 100K. I used CA3140 to buffer the LEDs and because I have a bunch of them lying around. I found using a rail to rail opamp works best in this config. Any pointers to equivalent but in one package?

I'd appreciate some opinions, tips or tops on this, it took me a while to come up with... 

Also the voltage drop I mention in the pic is what I measured with my MM, not the voltage at which the LEDs start to light up the slightest.




(edited pic, added resistor names)