I think it's something that happens to everyone.
Even when it looks good on my comp, I go elsewhere and it is not a "natural" color. Technology can sometimes be frustrating...
WH drakes would be about 1lbs heavier than KC, not sure how that translates size wise....either way, you have GORGEOUS birds! I tried vent sexing for the first time with my new ducklings to make sure they are all female, I got 2 KCs and by the looks of your drake I'm now kinda hoping I got one wrong. lol
Here is a link to a topic where they have pics of WH drakes
https://www.backyardchickens.com/forum/viewtopic.php?id=421143
Saxony drakes have more muted coloration- predominately a deep, rust colored red with underlying silver hues, the head and neck are a grayish blue, the neck has a white ring, dark eyes, dark yellow feet and bills. Couldn't find an example pic here, maybe someone else can help.
*You might want to take the word of someone more experienced than me, I am still learning and my knowledge is all based from books or others on the site. Really I am just another duck addict who loves to oggle at pretty birds.