Stuff said and WAY too many ellipsis
I like the idea that you're going with your color suggestions but they feel too disjointed. I don't think you should use the background sky as the predominant color on the keyboard because you are then making the whole kit based around one image, out of context, and not the WH40K universe, it won't translate.
I also think the creator needs to either decide if he wants a vague/general 40k set that represents the universe of 40k as a whole, in which case he needs a set that evokes the overarching themes of the universe, not one specific little part of it, or if he wants a set that is specific to one race/group/unit, in which case something closer to what you have laid out. But I agree with someone's above post that said he needs to refine this a lot more before asking people if they are interested, because right now there just isn't anything to be interested in. I don't think asking if people want a set based on a popular IP is enough for the IC community without a more developed set concept to work with.
I think you're on the right track with your renders, definitely better developed than what OP started with, but if you are going for Space Marines specifically, as an example, the majority color needs to be blue, since with the space marines, their tanks, their units, their banners, the primary color that takes up the most surface area is that blue color, the second most used color for them is gold, it's a huge accent color for them across the board and red and black share the spot as a tirtiary accent color.
I would offer something like making the Alphas Blue on Blue, Mods black with gold, red accent keys.. or something close to that would be a good direction to move toward with your renders, and read better for a Space Marines them. But the trick is going to be not stepping on the toes of already existing sets.