Green. The one color that is highly unacceptable and categorized as super 'unrealistic'.
But..what if instead of having it as a base or markings..why not have it as a mutation?

This is absurd! How is this even possible?! Now..I'm getting there in a moment. c;

Okay, how? Well, it's very rare (with only three cases of this happening in pups), but not harmful, and the cause of it is due to an exposure of biliverdin, a green bile pigment in the placenta.

Bile pigments are basically "-biological pigments formed in many organisms in many organisms as a metabolic product of certain porphyrins"

The color does eventually fade, but this mutation can be for those of you players who are all for green lions.

Examples shown here:


To find more about this mutation, click here.
Images and more are also here too

Update:
"I don't know if this would complicate things but maybe it could have complications in some cubs to be lethal like jaundice?"
Suggested by Nessus (#59)

"-maybe it could be for next years St. Patrick's day as a MOD release?"
Suggested by Arruru (#93355)

Feel free to share any comments or suggestions. ^^