He’s such a cutie. I’m not great on colour mutations, but to me, he looks like a normal colouring but he does have some yellow on his back and chest.
@Monica did help me with identifying my cockatiels colour mutation so they may be able to help you.
As for advice for taming him, I’ve recently got a cockatiel around a month ago so I can give you tips on how I successfully tamed and hand tamed my cockatiel. As you got him last week, he has had plenty of time to get used to his new surroundings in his cage and your home, so it is a perfect time to start taming him. What I did with my cockatiel, is I started to let him get used to the presence of myself and my hand (so he associates my hand with positivity). To do this, I just sat near my cockatiel’s cage and spoke to him (I would recommend reading to him), then slowly started to place my hand near the cage/leaned my hand on the outside of the cage for afew days until he got used to my hand.
Now that he’s gotten used to your hand near him, you can start to place your hand inside of the cage but not too near him for afew minutes about 3 times a day everyday. Once he gets used to your hand inside the cage, you can try to hold up a treat in your hand (I would recommend millet) and then slowly try to entice your cockatiel to get on your hand to eat the treat!
From there you can try teaching your cockatiel to step up, with this, take him into a separate room from his cage and put him on a stand (I would recommend getting a T-stand) and gently push your finger above his feet but below his chest and say “up”, when he does, reward him. Repeat this afew times a day everyday.
Here are afew more resources that I used to help me:
Tame cockatiels can be great fun for petting, playing, or even dancing to music, but it can take some time and effort to get to that point. When taming cockatiels, it's important to proceed slowly, training him or her in short sessions and...
www.google.co.uk
Hope this helped!