I would just like to mention a couple of things beforehand though before I share some pictures.
He is 2 years old. 2 months before he turned 2 he went to the vet for excessive watery stool. He got the full initial treatment: x-rays, out-of-lab blood work, fecal work. Everything came back normal, except that he had heightened protein levels. The vet and the pet store I purchased him from had told me that this could be a reason for his excessive yellow feathering.
However, I do have pictures of him before and after he turned 1. You can see, although very slight, few yellow spots and patches. However, months after he turned 1 I'm guessing he went through a slow molt and got more and more yellow.
As for diet, he had been on the same seed/pellet diet since he was weaned up until late May. My vet had me switch to Harrison's and now him and 2 of my other fids have converted to that while still getting fruits and veggies.
In late May they also got bird UVA/UVB lights. The pet store I got him from said this could actually make him more yellow instead in his next molt.
Last thing is that the breeder they got him from was not breeding something like a pied Senegal. The pet store said if he is something like this the breeder would've likely kept him back and not sold him to the store had they known.
Now for some pictures!
Baby Kisses:
4 months ago:
2 months ago. You can't see it but his back has some mild yellow feathering:
Four days ago:
