Make R200, R201 closer to 270 ohms, not 390 ohms. ronv's right, the inverters can go if you check the resistor calcs again.
I fell asleep and didn't get to go over thing with a fine tooth comb.
But just a reminder for LED driving (sourcing and sinking).
You have a term Vce(sat) usually from 0.2 to 0.8 volts
You have a supply voltage: 5V or slightly less than 5V (The 555 won't go to 5V, nor 0 volts) It will get close. You would use these numbers if directly driving LEDs from the output of the 555.
You have a LED voltage drop, called Vf. It's 1.2 V for the LCC110. Could be 2.1 or higher for other LEDs.
There is a min/max/typical drive current for LED's. 20 mA typical, 50-70 mA maximum. The LCC110 has a 8 mA typical. Would probably drive at 15-20 mA.
There is Vbr or V(reverse breakdown) for the LED and all diodes. The mechanism is usually non-destructive. Depends on design.
There is resistor power rating: (I^2)*R; 1/2 W should suffice
LEDs age, output does diminish over time. There is lots of variation.
Basic formula is (5-Vce-Vf)/I for that series resistor.
I had intended in one of the designs to place the LED's in the optocouplers in series, hence R was higher.
These guys:
https://www.electro-tech-online.com/custompdfs/2011/06/156946.pdf Bi-color 3-lead LED's are avialable in common anode/common cathode versions. Not a real common part, but usefull. They glow yellowish when the polarity alternates fast enough. That particualar part is from
www.jameco.com This is when panel space, cool factor come into play. I designed a peak detector, pulse extender and I used one. 50 Hz signal. If it exceeded +-10V, the approprite color showed up for 1 second, so you can see it.