A Shiro Utsuri (or other Utsuri) is quite difficult to judge at an early stage, because it is going to change dramatically. An Utsuri must develop over a long period of time and should not be "finished" too early.
The pectoral fins should be balanced. With your Utsuri, there are no Sumi in the one which makes it unbalanced.
The head should have both colours, almost 50/50. In your case, the head is basically white. The ideal is a pattern of black down the head called "Hachiwa" or a V across the head. However, any interesting pattern would do. You fish has no pattern, but it can develop, although unlikely.
The body of the fish should have more or less 50/50 shiro and sumi(black and white) and rather too many white than black. Remember that most of the black will still be deep and unfinished. This one might be too black, but a fairly good balance.
The black should not be represented by spots. It should rather have large patches like yours.
I do not like the black around the one eye. This will be a demerit.
In conclusion, this is not an ideal Utsuri, but remember, it might develop great.
As far as the Platinum Ogon is concerned, sorry to say, but I think it is not a good quality. The head is too dirty and black will gradually come through on the body. At this age, a Platinum Ogon should be all one colour with a good lustre and shine. It is still a good pond fish. I might be wrong, it is only my opinion and I will be glad for you if you can proof me wrong over the next few years.
Lets see what Pieter has got to say about your fish. Come on Pieter!
I agree with you that Platinums combined with Yamabuki's look great in a pond. The white and yellow creates a good contrast.
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