Comparator with Alternate LEDs
Try this.







simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. Modified output.

How it (might) work:


When CMP1 output is high D3 lights through R2.
When the open collector output of CMP1 is low D1 lights through R1. Meanwhile D2 steals the current from D3.


I haven't tried this and if the comparitor doesn't pull close to zero volts D2 may not pull the D3 voltage low enough to turn it off completely.

Let me know how you get on.