Mutation and gender

[InkD3ath]

Hi, so I'm new to the forum, and I have 2 cockatiels. One of them in pretty sure is a split pied male and the other I have no idea... except it's completely yellow and has no markings whatsoever that make it different. I wanted to know if someone could possibly tell me the mutation of gender of it.

[InkD3ath]

This is Roy and Totoro. I want to point out that I did not give them chocolate eggs and the red eye was just flash. also the second picture was when I first got Roy

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[Dragonlady2]

Welcome to the forum! Roy and Totoro are beautiful. I don't know anything about coloring...hopefully someone will be along to assist with this. They certainly look like they are questioning the size of those eggs...lol