So I think your choice of colors is great
But beyond that I think there are quite a few huge issues with the kit design.
First off, custom colors mean the price is inherently raised for each key as well as MOQ being 250 for each set individually, not total set sales. When people buy kits, they often shy away from sets where they need two or more kits to tip and one of the sets is low in sales.
Secondly, custom legends. You can pad print them, but that is honestly a bit of a waste for a GMK set. To make a custom mold with GMK the price is $500. Each. So quick math, to have a single custom legend set made, its going to be around $23,000. That will make the custom legend kit ~$160 if 250 people buy it (it essentially adds $90 to the cost of each kit at MOQ). Even a big set like YURI really had issues getting buyers for the Cyrillic kit, and Cyrillic sets have been one of the most popular non-english languages for years in this hobby. So trying to fund one, much less two brand new alpha kits is basically impossible at the current time.
Ergodox kit IS possible to succeed, but still is a fight. Being blank helps for sure. This isn't entirely unrealistic.
Novelties, with only 2, I'd work these into the base kit, help move the cost of those custom molds across all of the sets. If MOQ is met the cost per person will be nominal instead of trying to get 250 people just to buy that kit alone.
Finally, bars kit. This probably won't fly either. Bars are expensive. And as much as I think its great to think of supporting those odd layouts, at this point GMK is still just pretty difficult to do for them. People do ask for them, but when push comes to shove it never seems like the wallets are out for those kind of kits. Especially not 250 of them. Same for the Norde kit, I can pretty much guarantee that won't get remotely close to tipping.
If I were you I'd try to look at a lot of "all in one" sets and concentrate on a single manageable kit. You have some cool colors, that is the hard part and you did that well. If this was an SP set, I'd think it is realistic as it stands, but with GMK not so much.