Andy wrote:
>I need to generate Red, Amber-ish, and Green from a single LED body (standard
>T1.75 size).
>
>I am limited to a common-cathode device with two anodes to select the desired
>color.
>
>The P391 from Digi-Key doesn't blend the colors well when both LEDs are turned
>on, it's obviously a red and a green LED in the same package.
>

Try pulsing red and green on opposite phase, with various duty cycles
for different amber hues. To trick the eye, ie, to get persistence of
vision, use pulserate >> 25 hz.