After looking at Manu's younger brother Hikari, I have determined how genetics work in @NightSkyChoco 's universe
Hikari's "phenotype inheritance":
Almost Half of Hikari's body shape comes from Red's genes like his 2 folding crest feathers, straight tail feathers, black eyes, and 2 pointy crest feathers. Even though Red doesn't have the 2 pointy crest feathers, his brother, Remy does. This means the said gene was still in his genotype, but not in his phenotype (Physical Appearance). Hakari's body length, thin eyebrows, and curved beak come from Pekoe (his mother). Almost All of Hakari's color palate and feather pattern comes from Pekoe except for red accented "hair". His eyes come from Red.
Determining Manu's "phenotype inheritance":
Manu's beak shape, roundness, and hair fluff come from Red's side. Red's sister, Chie has whiskers are probably genetically modified versions of said hair tuff. Due to Red's cousin, Rovio having freckles, Manu's freckles likely come from his father's side. One of Manu's great grandparent's probably had freckles. Manu likely got his 3 2-tone crest feathers, round eyebrows, and round eyebrows from his mother. Manu got his spots and eyes from his father, and the rest of his palate from his mother.
What does this mean?:
When a bird is born, they will inherit close to half of their genes from their parents. They may inherit most of their color palate and feather pattern from their mother with a few exceptions.
What Manu's mother may look like:
Maroon base feather color
3 two-tone crest feathers
Brown Rounded eyebrows and tail feathers
