Fake sheep

I wanted to add a dye and all the functionality that comes with it including sheep. I wasn't able to add my dye the to pre existing sheep so I have my own fake sheep that spawn just like the real ones. However I'm having trouble making a procedure that know when it was born and not just spawned, and getting parent color when a sheep was just born to get the combined color of the parents like how the real ones do (eg: red sheep breeding with white sheep births a pink sheep)

I'm controlling the color with attributes and model layers if that's important

Is there a plugin to add a trigger to know when it was born or something to detect parent color.

Thanks in advance.